"gigantopterid" = an English noun describing large leaves with complex reticulate venation resembling the Cathaysian fossil seed plant genus Gigantopteris and North American genus Delnortea of the Permian Period, 260 million years ago"

You are here: Evolution of Mesozoic Angiosperms

ESSAY CONTENTS



[ Evolution of Mesozoic Angiosperms ]

JOHN M. MILLER, Ph.D.

University and Jepson Herbaria
Room 1001, Valley Life Sciences Building 2465
University of California, Berkeley
Berkeley, California, USA 94720-2465



Evolution of crown group flowering plants is discussed from molecular systematic- and paleobotanical research perspectives in this third of three essays on the origin of angiosperms. I also raise the issue of a possible ghost lineage of flowering plants and briefly review the literature on the basic biology and molecular evolution of extant basal angiosperms as defined by The Angiosperm Phylogeny Group (APG III 2009) to include enigmatic monocotyledonous Hydatellaceae (Friis and Crane 2007, Rudall et al. 2009, M. L. Taylor et al. 2010, Prychid et al. 2011).

A Mesozoic radiation of angiosperms is discussed below in the context of the APG III proposed classification (Chase and Reveal 2009) and a book chapter dealing with the subject of angiosperm evolution (Dilcher 2010).

The previous essay raises the possibility that flowering plants might be an amalgam of paraphyletic evolutionary lines traceable to surviving geographically disparate early Triassic remnants of already divergent Permian seed plant lineages. This idea is supported by reanalysis of nucleic acid data suggesting a late Triassic age for the flowering plant crown group (Stephen A. Smith et al. 2010).

Molecular phylogenetic analyses by Magallón (page 395, 2010) when calibrated with fossil data and compared with different relaxed clock methods "... imply that the diversification that lead to living angiosperm species began sometime between the Upper Triassic and the early Permian."

Ancient WGDs are implicated in both the common ancestor of eudicots and monocots and in the MRCA roughly coinciding with the Frasnian-Famennian boundary extinction (DeCARB) and Triassic-Jurassic boundary carbon cycle event (TrCCE).

Genomic studies of the cultivated grape overwhelmingly support paleohexaploidy (Jaillon et al. 2007), which is equivalent to the "γ triplication" cited by Jiao et al. (2011) that occurred in the common ancestor of eudicots and monocots.

Do crown group flowering plants, in fact, represent a loose amalgam of several parallel evolutionary lines? Possibly, but much more hard work is needed to detect paraphylesis in deep time, if paraphyly (and/or reticulation) exists at all along the stem (or stems) of the angiosperm tree.

The picture of the rock slab above is of an indeterminate eudicot fossil flower (IU15713-3429) from the Lower Cretaceous Dakota Formation of North America (photographed with the permission of Professor David L. Dilcher in 1981).

Earlier, I placed on the table a proposal that evolutionary development (evo-devo) of protoflowers and adaptive radiation of certain clades of coevolving Holometabola might be traceable to selective pressures behind molecular coevolution of insect and seed plant developmental cis-acting regulatory modules (CRMs) in deep-time.

Students of seed plant phylogenetics should be open to the logical suggestion that 300 million year old Carboniferous hermaphroditic seed plants, specifically species of Vojnovskyales, should be included in updates of lignophyte phylogenies now that biochemists implicate spermatophytes with bisexual cone axes as key players in explicit models of MIKC-type MADS-box B gene regulation by protein quartets and phytohormone gradients (Theißen and Becker 2004).

Finally, I concluded in the first two essays that insect mediated intergeneric natural hybridization among populations of gigantopteroids and vojnovskyaleans, followed by spontaneous paleopolyploidy, might have been a method through which MIKC-type MADS-box gene duplicates were generated, later spreading molecular novelties in populations of the ancestral, putative early Triassic ghost lineage(s) of angiosperms that survived the end-Permian mass extinction (EPE).

The next chapter discusses the fossil history and paleobiodiversity of Mesozoic angiosperms. The numbering of tables in this chapter follows Table 5, Anthophytes, Conifers, and Gigantopteroids without Core Pteridosperms: Character Data Matrix Process ANTHO, which is located near the end of the previous essay on the Paleobotany of Angiosperm Origins.


Stem Group Flowering Plants:

Flowering plants are the most successful group of land plants on Earth. According to a review by Crepet and Niklas (page 368, 2009), ideas on the diversification and success of angiosperms "fall into one of three camps: ..."

  • hypotheses that focus on vegetative attributes such as diverse anatomy, phenotypic plasticity, rapid growth rates, and high hydraulic conductivity;
  • hypotheses on the adaptability and efficiency of reproductive modules such as floral display, pollination ecology, embryology, and fruit and seed dispersal and ecology; and
  • hypotheses that incorporate a discussion of innovative developmental tool kits (to confer plasticity) and elaborations of secondary biochemical pathways needed to manufacture natural plant products in the arsenal for the coevolutionary arms race.
  • A fourth, ecologically-grounded soil nutrient-feedback hypothesis is advanced by Berendse and Scheffer (2009).

    "Did insect pollination cause increased seed plant diversity?" (Gorelick 2001). These questions, among others (Berendse and Scheffer 2009, Crepet and Niklas 2009) should now be discussed from a late Paleozoic temporal perspective based on evidence presented in the first and second essays.

    Angiosperm ghost lineage. There is growing consensus among some molecular systematists and paleobotanists on the existence of a 160 million year old angiosperm ghost lineage rooted at the angiosperm-gymnosperm split roughly 300 MYA, prior to the end-Permian extinction. Calibrating the timing of this split together with the other Great Late Paleozoic Seed Plant Divergences, using guide fossils, will be important exercises in future combined molecular- and morphological-phylogenetic analyses.

    A possible paraphyletic Paleozoic origin of angiosperms contradicts proposals by Leebens-Mack et al. (2005) suggesting a monophyletic Mesozoic origin of a basal clade of flowering plants, which is based on estimates derived from cpDNA data.

    Employing refined methods to estimate rates of divergence of flowering plants, Charles Bell and colleagues (2010) publish a milestone paper based on more than 500 extant taxa and 35 calibration points.

    Ancestors of putative paraphyletic grades of angiosperms might have been Permo-Carboniferous or Permo-Triassic gymnosperms with hermaphroditic (bisexual) strobili.

    I also built a case and presented evidence in the second essay that some of the candidate gymnosperm groups with bisexual protoflowers are presently known only from detached taeniopteroid sporophylls and foliar tepals of Ginkgo-like spur shoots, and subtending gigantopteroid megaphylls. Permian delnorteas and evolsonias probably fit this bill but more paleobotanical field work is needed to match the detached pieces to the whole mother plant.

    The drawing to the right is Lesqueria elocata (family uncertain, Magnoliales, Magnolianae) from page 399 of Crane and Dilcher (1984), Lesqueria: an early angiosperm fruiting axis from the mid-Cretaceous, Annals of the Missouri Botanical Garden 71(2): 384-402, reproduced by permission from Peter Crane, David Dilcher, and the Missouri Botanical Garden.

    "Figure 47. Reconstruction of the Lesqueria elocata fruiting axis."

    This statement by Wing and Boucher (page 380, 1998) is probably incorrect: "Despite the singular ecological significance and species diversity of angiosperms, they are not in a genealogical sense one of the major branches of land plants and did not originate with other major land plant clades (e.g. lycopsids, ferns, conifers, cycads, ginkgos) during the middle or late Paleozoic."

    Feild and Arens (2007) are probably also on thin ice when asserting that flowering plants originated in specific terrestrial paleoenvironments during the earliest Cretaceous Period. Simply put, apparent absence of angiosperm fossils in the Triassic and Jurassic stratigraphic record is not data.

    Absence of paleobotanical data is not a substitute for fact when dealing with a probable ghost lineage due to insufficient sampling, especially in view of more than a dozen molecular phylogenetic studies pointing to ancient gene duplications and deep time divergences between angiosperms and its nearest relative (S. Kim et al. 2004, D. E. Soltis et al. 2007, Jiao et al. 2011).

    In terms of paleopolyploidy, one or more gene duplications in the APETALA3/PISTILLATA (AP3/PI) B-class MADS-box gene lineage might have paved the way for the evolutionary development of proanthostrobili 290 MYA (S. Kim et al. 2004). Genomic data on the timing of WGDs (Jiao et al. 2011) will require calibrating with well-dated guide fossils to be selected by paleontologists.

    Unequivocal stem group angiosperms remain unknown (D. E. Soltis et al. 2007, Stephen A. Smith et al. 2010) despite the assertion of other workers that "considerable progress" appears in the literature on identifying "the earliest lineages of flowering plants" (page 1581, Rudall et al. 2009).

    Another "nail in the coffin" holding the Cretaceous angiosperm origin line of thinking comes from reanalysis of relaxed clock nucleic acid data (Stephen A. Smith et al. 2010), and molecular phylogenetic studies of the Class III HD-Zip gene family, which points to a gene duplication event leading to the PHABULOSA/PHAVOLUTA-related and CORONA/HB8-related clade more than 300 MYA during the Carboniferous Period probably before the angiosperm-gymnosperm split (Prigge and S. E. Clark 2006).

    Based on this fragmentary body of sometimes credible data, a 160 million year old ghost lineage or lineages of flowering plants is likely, thus paralleling the vexing problems in deciphering early Mesozoic insect and dinosaurian lineages, including challenges to the validity of the so-called Cretaceous Terrestrial Revolution (G. T. Lloyd et al. 2008). More paleontological data are critically needed in line with suggestions by E. L. Taylor and T. N. Taylor (2009).

    Vivian Irish (2006) provides a road map to diversification of the angiosperm clade from the perspective of evo-devo of floral homeotic genes, their phenotypic expression, and molecular phylogenies. Most of the explosive radiation of floral diversity in basal lineages of flowering plants is explained by duplication and diversification of the MIKC-type MADS-box family of genes (P. S. Soltis et al. 2009).

    The many studies reviewed by J. A. Doyle and Endress (2000), Endress and J. A. Doyle (2009), Hileman and Irish (2009), Rasmussen et al. (2009), P. S. Soltis et al. (2009), Specht and Bartlett (2009), and Melzer et al. (2010) are a foundation for inferring the morphology of the ancestral angiosperm flower and determining the phylogenetic position of derived modern flowering plant groups.

    While discussing their perception of the flower "... and its initial evolutionary modifications ..." within the context of extant basal angiosperms, Endress and J. A. Doyle (2009) state:

    "It is unlikely that this 'ancestral flower' was the 'first flower' in a morphological sense, which may have originated much earlier on the angiosperm stem lineage ..."

    The preceding two quotations are from page 23 of P. K. Endress and J. A. Doyle. (2009), Reconstructing the ancestral angiosperm flower and its initial specializations. American Journal of Botany 96(1): 22-66.

    The remaining sections of this third and last essay review high points of the vast literature that covers the Mesozoic fossil history of crown group flowering plants. There is brief mention of extant plant biology and phylogenetics to accompany these paleobotanical snapshots. Accomplished albums on Cenozoic paleobotany and insect biology are published in key books by T. N. Taylor et al. (2009), and Grimaldi and Engel (2005), respectively.

    Angiosperm classification. It is important to review the phylogenetic position and naming of modern flowering plant groups within a general evolutionary framework for purposes of later comparison and discussion. I reject proposals to abandon the Linnean system of nomenclature and replace it with a sophomoric phylocode.

    Professor Tod Stuessy (2009) presents cogent arguments refuting attempts by others to adopt an unnecessary phylocode.

    Classification levels of order and genus are used in the tabulations below because the number of genera in extant floras is the most commonly used biogeographically significant measure of biodiversity. Principal references on angiosperm classification and floristics are Engler (1964), Thorne (1968), Dahlgren (1980), Cronquist (1981), Dahlgren and Clifford (1982), Dahlgren et al. (1985), Thorne (1992), Takhtajan (1997), Thorne and Reveal (2007), Angiosperm Phylogeny Group (2009), Chase and Reveal (2009), Endress and J. A. Doyle (2009), and Takhtajan (2009).

    Cladistics is a scientific tool with mathematical and theoretical limitations (Graur and Martin 2004) that should not be a final determinant of classification (Stuessy 2009). It (cladistics) is not a "science" in my opinion, despite Cracraft's statement (page 348, 2005).

    "The only way to identify fossil stem relatives of angiosperms is by consideration of their morphological characters, preferably analyzed with cladistic methods."

    The preceding statement is quoted from page 819 of J. A. Doyle (2008), Integrating molecular phylogenetic and paleobotanical evidence on the origin of the flower, International Journal of Plant Sciences 169(7): 816-843.

    The graphic below is redrawn from APG III (page 108, Figure 1, 2009). The APG III phylogenetic tree shows relationships of some families and orders of angiosperms supported by jackknife and bootstrap frequencies over 50% or Bayesian posterior probabilities > 0.95 (not all flowering plant families are included), based on molecular data (APG III 2009).

    Molecular phylogenetic studies of extant flowering plants now incorporate the nuclear gene Xdh (Morton 2011).

    Douglas Soltis and co-workers offer one of several updates of the ongoing research effort to compute the angiosperm tree of life from molecular data (D. E. Soltis et al. 2010). A companion to APG III is published as an updated molecular based phylogeny of flowering plants by D. E. Soltis et al. (2011), which incorporated studies of 17 genes and 640 species.

    The color of typescript in the remainder of figures on this web page allows visual cross reference to subclasses of flowering plants (Cronquist 1981) where a discussion of characters is available. Monocots are in various shades of green or orange (Alismatidae are denoted by blue-green type, Arecidae with yellow type, Zingiberidae are shown in gold letters, Commelinidae have green letters, and Liliidae are depicted in lime green type).

    Magnoliidae are shown with indigo brown type. Hamamelidae are depicted with magenta letters. Dilleniidae appear on the dendrogram labels in royal blue. The Caryophyllidae are depicted in purple type. Rosidae are colored red and Asteridae appear in black type.

    Fossil history. Fossilized pollen casings known as palynomorphs are known from middle Triassic sediments recovered from deep well bore holes drilled off the island of Spitzbergen (Hochuli and Feist-Burkhardt 2004). These palynomorphs may represent the first Mesozoic records of stem group angiosperms, but whole plant fossils are lacking (Friis et al. 2005).

    A review of Cretaceous records for clumped angiosperm pollen and its bearing on coevolution with insect pollinators is available (D. W. Taylor et al. 2010).

    Uncanny similarities of early Mesozoic seed plant Sanmiguelia lewisii (Cornet 1986, 1989) with Paleozoic Vojnovskyales pointed out by Crane (1985) require confirmation by cladistic analysis of reproductive and vegetative characters gleaned from detailed anatomical studies of more fossilized remains to be collected. This is an unstudied chronocline with potentially profound implications toward the idea of paraphyletic transitions in diverging seed plants at the base of the angiosperm stem(s) that straddle the PTr boundary.

    Triassic angiosperm-like fossils of detached "dicot-like" leaves described as Pannaulika triassica are known (Cornet 1993). However, the Pannaulika leaf find requires discovery of attached sexual organs and stems. Past interpretations of poorly-preserved, crumpled reproductive structures of the Sanmiguelia seed plant are controversial and the subject of much debate.

    Friis et al. (2005) underscore the importance of studying poorly known Mesozoic gymnosperms in order to elucidate the roots of the angiosperm stem group. I concur. Stem group flowering plants are almost completely unknown except for tantalizing clues to their existence from fossil finds of angiosperm palynomorphs, which were recovered from deeply buried Middle Triassic sediments and later discussed by Hochuli and Feist-Burkhardt (2004).

    Comprehensive accounts of the past literature on Mesozoic angiosperms are published by Dilcher (1979), Crane et al. (1986), Crane and Herendeen (1996), Crepet et al. (2004), Friis et al. (2006), and Friis et al. (2009).

    Fossils of several other enigmatic flowering plants have been recovered from Mesozoic rocks but reproductive details and the morphology of whole plants are unclear due to problems with poor preservation and uncertain stratigraphic control (Müller 1981, G. Sun and Dilcher 1997, G. Sun et al. 1998, G. Sun et al. 2001, Friis et al. 2006, X. Wang et al. 2007).

    Several angiosperm-like extinct groups of seed plants including indeterminate plants that shed ephedroid seeds assignable to the Bennettitales-Erdtmanithecales-Gnetales group (Friis et al. 2009), corystosperms (Frohlich 2002, Stockey and Rothwell 2009), and pentoxylaleans coexisted in the Cretaceous Period with certain modern flowering plant groups. Corystospermales represented by the Paleogene Tasmanian fossil Komlopteris cenozoicus, and Bennettitales suggested by Ptilophyllum muelleri are the only two groups of seed ferns that survived the K-T asteroid impact (McLoughlin et al. 2008, McLoughlin et al. 2011).

    I completely reject the assertion by some workers that angiosperms first appeared in the Cretaceous Period (Feild and Arens 2007). Absence of fossilized remains of flowering plants in the stratigraphic record is not data.

    Table 6 summarizes the stratigraphic distribution and microfossil, megafossil, and mesofossil history of the subclasses of flowering plants according to Cronquist (1981). I did not include numerous reports and descriptions of Mesozoic leaf morphotype genera (Dilcher and Basson 1990, Upchurch and Dilcher 1990, among others) to avoid guesswork on their taxonomic placement without benefit of reproductive structures.

    Detailed discussion is published in Chapter 22 of the most recent comprehensive treatise on fossil angiosperms (T. N. Taylor et al. 2009). The data contained in T. N. Taylor et al. (2009) are more complete and detailed than my brief summary (Tables 6-13).

    "Angiosperm phylogeny is riddled with examples of convergent morphologies ... Any classification based on a single organ has a greater potential for error than one based on a variety of organs ... Although one solution to this problem would be to restrict the systematic analysis of angiosperm megafossils to taxa known from both reproductive and vegetative organs, this approach would greatly restrict information about the flora as a whole, given the dominance of isolated vegetative organs in the megafossil record."

    The above statement is from page 3 of Upchurch and Dilcher (1990), Cenomanian Angiosperm Leaf Megafossils, Dakota Formation, Rose Creek Locality, Jefferson County, Southeastern Nebraska, U.S. Geological Survey Bulletin 1915.

    Integers in Table 6 represent the total number of taxonomic orders and genera (in parentheses) for each of Cronquist's subclasses of flowering plants. Separate columns are devoted to extant and extinct taxa. The number of extant genera (in parentheses) in the table below was compiled from Cronquist's family descriptions (1981). Certain fossil species reported in the scientific literature are not assignable to any extant angiosperm subclass. The Archaemagnoliidae is lumped with the Magnoliidae.


    Table 6. Mesozoic Fossil History of Subclasses, Orders, and Genera of Flowering Plants According to Cronquist (1981).

    Taxonomic Subclass

    Extant Orders (Genera)

    Mesozoic Orders (Genera)

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Not Assignable to a Known Subclass

    Not Applicable

    ?(7)

    0

    ?(2)

    ?(4)

    ?(4)

    Alismatidae

    4(60)

    2(4)

    0

    1(2)

    1(2)

    ?

    Arecidae

    4(330)

    3(11)

    0

    1(1)

    1(1)

    3(5)

    Asteridae

    11(3584)

    ?(2)

    0

    0

    0

    2(2)

    Caryophyllidae

    3(397)

    1(1)

    0

    0

    0

    1(1)

    Commelinidae

    7(703)

    1(1)

    0

    0

    0

    1(1)

    Dilleniidae

    13(1452)

    5(11)

    0

    0

    3(4)

    5(7)

    Hamamelidae

    11(148)

    3(18)

    0

    0

    3(13)

    5(24)

    Liliidae

    2(1463)

    1(1)

    0

    0

    1(1)

    1(1)

    Magnoliidae

    8(482)

    6(42)

    0

    4(5)

    10(32)

    2(5)

    Rosidae

    18(3185)

    10(23)

    0

    0

    5(12)

    9(19)

    Zingiberidae

    2(134)

    1(2)

    0

    0

    0

    1(1)


    There is a significant increase in the number of orders and genera of fossil flowering plants by the Aptian Age of the Gallic Epoch of the Cretaceous Period, based on data in Table 6. When the compression floras of leaves are added, a late Cretaceous radiation of angiosperms is remarkable (Friis et al. 2006).

    The Cretaceous to Neogene "Assemblage 4: Angiosperms and the Later Phase of the Modern Insect Fauna" (page 254, Labandeira 2000) is concordant with the view that, "... no other reason than flowering plants and holometabolous insects essentially have monopolized almost all of the terrestrial (and many freshwater) habitats during this interval ..."


    Crown Group Flowering Plants:

    This chapter reviews the scientific literature on the basic biology of extant basal angiosperms of the crown group, and summarizes the fossil record of magnoliids, monocots, eudicots, and core eudicots (rosids and asterids).

    Insights into the rapid radiation of crown group flowering plants from the angiophyte stem group based on contrasting molecular phylogenetic research perspectives are available in numerous reviews (J. A. Doyle and Donoghue 1993, Magallón and Castillo 2009, Stephen A. Smith et al. 2010, Burleigh et al. 2011, D. E. Soltis et al. 2011), among others.

    Pictured to the left is a flower of Protea compacta (Proteaceae, Proteales, Proteanae) photographed by the author.

    Molecular phylogenetic studies suggest that differentiation of flowering plants into a Mesozoic stem and crown group is feasible (Hilu et al. 2003, Davies et al. 2004, Leebens-Mack et al. 2005, R. K. Jansen et al. 2007, Stephen A. Smith et al. 2010, Burleigh et al. 2011, D. E. Soltis et al. 2011), among others.

    The Cretaceous Yixian Formation of Asia yields potentially interesting fossilized inflorescences, flowers, seed, and pollen of crown group angiosperms including Asiatifolium, Jixia, Leefructus, Shenkuoa, and Xingxueina (G. Sun et al. 2001, G. Sun et al. 2011). Many of these fossil genera probably belong in the lower eudicot or magnoliid clades.

    Research findings on the Cretaceous Yixian Formation and other strata from northeastern Asia are reviewed by Ge Sun et al. (2008) and G. Sun et al. (2011).

    Archaefructus liaoningensis (Magnoliophyta, Magnoliopsida, Archaemagnoliidae), has been described (G. Sun and Dilcher 1997) and discussed within the context of a Jurassic aquatic origin of flowering plants (G. Sun et al. 1998). Radioisotope decay data suggest that the Yixian Formation is much younger than originally believed by Ge Sun and colleagues (see Friis et al. 2006).

    Phylogenetic placement of Archaefructus as a stem group flowering plant is problematic (Friis et al. 2003, J. A. Doyle 2008). Several workers suggest that the angiosperm fossils from the Cretaceous Yixian Formation are better placed with the crown group of eudicot angiosperms.

    Hyrcantha decussata (Sinocarpus decussatus, Leng and Friis 2006) is one of the controversial angiosperm-like fossils recovered from northeastern Asian Cretaceous sediments (Dilcher et al. 2007). It is increasingly unlikely that any of the aforementioned taxa belong in the angiosperm stem group.

    Fossilized flowers are also known from exposed Cretaceous sediments of Antarctica (Eklund 2003), Asia (G. Sun et al. 1998, Poinar and Chambers 2005), North America (Crane and Herendeen 1996), South America (Endressinia brasiliana, Mohr and Bernardes-de-Oliveira 2004), and elsewhere (Friis et al. 2006), among others.

    Another interesting but incomplete Cretaceous North American angiosperm fossil is Archaeanthus linnenbergerii (Dilcher and Crane 1985). The morphology of pollen-bearing organs and stem anatomy of Archaeanthus is unknown, therefore critical comparison with Afropollis pollen and fossil wood of Cretaceous Winteraceae from Antarctica (Poole and Francis 2000) is impossible.

    "It seems the perpetuation of the 'abominable mystery' is due more to a disagreement over the cladistic position of various fossil taxa in relationship to the angiosperm crown group, than the lack of data."

    The preceding quotation is from page 127 of M. S. Zavada (2007), The identification of fossil angiosperm pollen and its bearing on the time and place of the origin of angiosperms, Plant Systematics and Evolution 263: 117-134.

    The APG III classification system (Chase and Reveal 2009) will require revision to accommodate results of ongoing molecular phylogenetic research (D. E. Soltis et al. 2011). Some workers in the past (D. E. Soltis and P. S. Soltis 2003) suggested abandoning the angiosperm subclass system enthusiastically followed by Arthur Cronquist (1981) and others, but this idea might be too inflexible, in my opinion.

    A temporary fix to preserve Arthur Cronquist's accomplished work is to adopt the classification level of superorder as championed by Dahlgren and Clifford (1982) and Dahlgren et al. (1985) for monocots, and proposed by Chase and Reveal (2009) for flowering plants as a whole. Some Cretaceous angiosperm and mesoangiosperm fossils do not fit in Chase and Reveal's superorders, therefore an informal approach is warranted here.

    Tables 7-13 are organized along the lines adopted in T. N. Taylor et al. (2009) with consideration of updated concepts introduced by Chase and Reveal (2009).

    Cretaceous explosive radiation of angiosperms. Rapid radiation of flowering plants during the Albian Age of the early Cretaceous Period is demonstrable based on paleontologic evidence gathered to date (Friis et al. 2006, T. N. Taylor et al. 2009, Friis et al. 2010), molecular evidence from duplication and neofunctionalization of MIKC-type MADS-box genes (Irish 2006), and phylogenetic analyses (D. E. Soltis et al. 2008, Endress and J. A. Doyle 2009).

    McElwain et al. (2005) suggested that the Cretaceous diversification of flowering plants was possibly attributable to decline in atmospheric carbon dioxide levels instead of developing aridity. Rapid radiation of angiosperms might have been "controlled by ecological limits" (abstract, J. C. Vamosi and S. M. Vamosi 2010), or diversification was affected by escalation (Vermeij 2011).

    Wildfire regimes were probably responsible for the rapid spread of the group in Cretaceous times (Belcher 2010).

    Boyce and Lee (2010) suggested that the rise of dominance of angiosperms played a critical role in tropical rainforest biodiversity and expansion from an ecophysiological research perspective.

    Clues to angiosperm diversification may be gleaned from studies of xylem heterochrony (Carlquist 2009).

    Was the Big Bang of angiosperm evolution during the Aptian Age (Gallic Epoch) attributable to the effects of the end-Barremian Age (Neocomian Epoch) biogeochemical perturbation (BaCCE) on coevolving angiosperm hosts and insect antagonists?

    The oldest fossil eudicot, Leefructus, is from Lower Cretaceous units of the Yixian Formation radiometrically dated within the interval 123-124 MYA, which is the Barremian Age (G. Sun et al. 2011).

    Mounting geophysical evidence points toward extensive episodes of Cretaceous (Aptian) volcanism in the southwest Pacific Basin near the undersea Ontong Java Plateau (Tejada et al. 2009). Methane clathrates released from undersea beds could explain significant spikes in atmospheric methane and carbon dioxide, triggering the BaCCE and later carbon cycle anomalies of the Cretaceous Period.

    Heimhofer et al. (2005) suggest that the BaCCE might have accelerated the diversification of early magnoliid flowering plants and possibly monocots. Phylogenetic analysis supports the idea that an explosive radiation of the order Malpighiales occurred during the Aptian Age of the Gallic Epoch, a few million years after the BaCCE (Davis et al. 2005, Figure 1).

    In 1981, Friis and Skarby reported a remarkable find of abundant indeterminate and tiny angiosperm eudicot flowers from the Late Santonian-early Campanian Age (Senonian Epoch, Late Cretaceous Period). Friis and Skarby (1981), Friis (1985), Crane et al. (1986), Knobloch and Mai (1986), Schönenberger and Friis (2001), Eklund (2003), Kvaček and Eklund (2003), and Friis et al. (2006) are key pieces of the scientific literature on early angiosperm floras and fossils.

    Studies of Cretaceous permineralized woods (V. M. Page 1967) paint a different picture of Maastrichtian forests once thought to be dominated by gymnosperms. A recent study of wood permineralizations sampled from large, fallen in situ logs from southwestern North American Maastrichtian (Senonian) deposits of the Aguja and Javelina Formation suggests that "dicotyledonous" trees were more abundant than conifers. Petrified stumps of Javelinoxylon multiporosum (Malvales, Dilleniidae) were more than a meter in diameter with extrapolated tree axes up to 40 meters tall (Wheeler and Lehman 2000).

    Existence of dilleniid Javelinoxylon trees belonging to derived crown group eudicots as an important floristic element of late Cretaceous stratified tropical forests of southwestern North America (Wheeler and Lehman 2000), and large trees of Paraphyllanthoxylon indigenous to European forests of that time (Oakley and Falcon-Lang 2009), detract from the idea that early flowering plants were paleoherbs of upland habitats.

    A paper by Bond and A. C. Scott (2010) suggests that "novel fire regimes" affected the rapid diversification and evolution of crown group flowering plants.

    Basal angiosperms. The floral biology and evolution of basal angiosperms and magnoliids is reviewed by Peter Endress (2010). An APG update (APG III 2009) includes a "working classification" (pages 123 and 124, Table 1, Chase and Reveal 2009), which I adopted in this essay.

    The water lily above is Nymphaea odorata var. rosea (Nymphaeaceae, Nymphaeales, Nymphaeanae).

    A benchmark phylogenetic study by Y.-L. Qiu (2000) established a group of extant flowering plant families as basal to all other living angiosperms. Phylogenetic inference from genomic data including more than 18,000 gene trees by Burleigh et al. (abstract, 2011) supports placement of magnoliids as "sister to a eudicot + monocot clade."

    Chase and Reveal (2009) recognize four superorders of basal angiosperms and magnoliids: Amborellanae, Austrobaileyanae, Magnolianae, Nymphaeanae. Chloranthales are unplaced (Chase and Reveal 2009).

    The classification proposed by Chase and Reveal (2009) for angiosperms is accompanied by a scheme for extant gymnosperms, which is published by Christenhusz et al. (2011).

    Certain ANITA grade basal flowering plants first appear in the fossil record of the Cretaceous Period (Friis et al. 2000, Friis et al. 2001, Krassilov and Golovneva 2004, Takahashi et al. 2007, von Balthazar et al. 2008). The fossil history of basal angiosperms is reviewed by Friis et al. in three reviews (2006, 2009, 2010).

    Douglas E. Soltis et al. (2005) provide a detailed discussion of basal flowering plants which is updated in a recent review (D. E. Soltis et al. 2008). Alexandr Rasnitsyn and Donald Quicke (2002) edit the most complete book on Triassic, Jurassic, and Cretaceous fossil insects available at this time.

    A book on Mesozoic seed plants including crown group basal angiosperms is T. N. Taylor et al. (2009). The extensive discussion, graphics, and tables presented in the four monumental works cited above will not be repeated here; however data are cited when appropriate.

    D. E. Soltis et al. (2005) support the assignment of ANITA grade angiosperms to a basal position in several calibrated, bootstrap supported, molecular-based phylogenies of extant flowering plants. The acronym ANITA is composed of first letters from the taxa Amborella, Nymphaeales, Illiciaceae, Trimeniaceae, and Austrobaileyaceae.

    Since 2005 phylogenetic analyses of extant basal flowering plants point to the Amborellaceae, Nymphaeales, and Austrobaileyales (ANA) as sister groups to all other basal magnoliids, monocots, eudicots, core eudicots, rosids, and asterids (Leebens-Mack et al. 2005, Y.-L. Qiu et al. 2006, Frohlich and Chase 2007, D. E. Soltis et al. 2008, Magallón and Castillo 2009). Reevaluation of gymnosperm molecular sequences when subjected to phylogenetic analysis (Y.-L. Qiu et al. 2001) support the basal position of ANITA grade angiosperms with respect to magnoliids, monocots, and eudicots.

    A review and phylogenetic analysis incorporates early Cretaceous fossil data with input from extant basal angiosperms and magnoliids (J. A. Doyle and Endress 2010).

    Basal flowering plants sensu Cronquist (1981) belong to Amborellaceae and Trimeniaceae (Laurales), Austrobaileyaceae (Magnoliales), Hydatellales (monocots), Illiciales, and Nymphaeales.

    Certain other Magnoliales once regarded by Cronquist (1981) as primitive angiosperms (Annonaceae, Degeneriaceae, Lactoridaceae, Magnoliaceae, and Winteraceae) are in a more derived position on phylogenetic trees based on molecular data (Wikström et al. 2001, Davies et al. 2004, Leebens-Mack et al. 2005, Y. L Qiu et al. 2006, D. E. Soltis et al. 2007) than ANITA grade taxa.

    Tremendous progress has been made on understanding the anatomy, basic biology, organelle genetics, developmental genetics, ecology, floral genetics, molecular evolution, morphology, natural history, and phylogenetic systematics of ANITA grade basal angiosperms (Parkinson et al. 1999, J. A. Doyle and Endress 2000, Endress and Igersheim 2000, Floyd and Friedman 2000, S. W. Graham and Olmstead 2000, Mathews and Donoghue 2000, Y. L Qiu et al. 2000, P. S. Soltis et al. 2000, and Thien et al. 2000).

    Work on ANITA grade basal angiosperms is published by Endress (2001), Furness and Rudall (2001), Friedman (2001), Yamada et al. (2001), Borsch et al. (2003), Feild et al. (2003), Ronse De Craene et al. (2003), E. L. Schneider et al. (2003), Zanis et al. (2003), Aoki et al. (2004), Endress (2004), Stefanovič et al. (2004), Carpenter (2005, 2006), Endress and J. A. Doyle (2007), Feild and Arens (2007), Rudall et al. (2008), Endress (2008), Sage et al. (2009), P. S. Soltis et al. (2009), Thien et al. (2009), and Zuccolo et al. (2011), among others.

    Despite elucidation of MIKC-type MADS-box gene function in several groups of flowering plants (Irish 2006), the importance of MIKC-type MADS-box A function in basal angiosperms is unclear (D. E. Soltis et al. 2007). Molecular phylogenetic work has been published by S. Kim et al. (2005), Leebens-Mack et al. (2005), Podoplelova and Ryzhakov (2005), Y. L Qiu et al. (2005), Zahn et al. (2005), P. S. Soltis et al. (2006), Moore et al. (2007), D. E. Soltis et al. (2007), and P. S. Soltis et al. (2009).

    Zahn et al. (2005) report MIKC-type MADS-box E gene homologs of SEP from basal angiosperms. The molecular phylogenetic studies by Zahn et al. (page 2220, 2005), "strongly supports the hypothesis that the SEP subfamily has been present in the angiosperms since before the diversification of the extant basal-most angiosperms Amborella and the Nymphaeales."

    Pollination ecology of primitive flowering plants has the subject of much field research and debate over the past 20 years, even before the term basal was widely used by plant systematists. Certain beetles (Coleoptera) are considered pollinators of basal angiosperms but the list also includes several groups of flies (Diptera), moths (Lepidoptera), and wasp-like bees (Hymenoptera). A review of some of these studies (Bernhardt et al. 2003) adds considerable controversy to the role of stigmatic secretions as pollinator attractants, and calls into question character polarity of wet type stigmas determined by Endress and Igersheim (2000).

    Amborellanae. Key research papers that focus on Amborellanae include I. W. Bailey and Swamy (1948), Tobe et al. (2000), Endress and Igersheim (2000), Feild et al. (2001), Hesse (2001), Yamada et al. (2001), Goremykin et al. (2003), Posluszny and Tomlinson (2003), Thien et al. (2003), Bergthorsson et al. (2004), Buzgo et al. (2004), D. E. Soltis and P. S. Soltis (2004), Yamada et al. (2004), Duarte et al. (2008), D. E. Soltis et al. (2008), Friedman and Ryerson (2009), and Williams (2009), among others.

    Basalmost position (or near basalmost) of the angiosperm crown group species Amborella trichopoda in some molecular based phylogenies is challenged by Goremykin et al. (2003). This seemingly anomalous finding is explained and eloquently refuted in two papers (D. E. Soltis and P. S. Soltis 2004 and Stefanovič et al. 2004).

    Apart from the possibility that the Amborella genome may not show evidence of extensive WGDs (D. E. Soltis et al. 2008), it is troubling that YABBY2 genes in the species are expressed on adaxial leaf surfaces (Yamada et al. 2004).

    Nuances illuminated by evo-devo and molecular systematic studies of Amborella trichopoda might be explained when its genome is sequenced. Genomic studies are in progress (Zuccolo et al. 2011). From the research perspectives of molecular coevolution, paedomorphic heterochrony, and reproductive biology, the most curious finding uncovered thus far by the Amborella Genome Project is "that the density of long terminal repeat retrotransposons is negatively correlated with that of protein coding genes" (abstract, Zuccolo et al. 2011).

    Further, it is probably important for these workers to sequence the genomes of other basal flowering plants including water lilies and magnoliids for syntenic comparison with Amborella and avocado.

    Nymphaeanae. Nymphaeales have been studied by numerous students of ANITA grade angiosperms including Yamada et al. (2003), Dorn et al. (2004), Les et al. (2004), Vogel and Hadacek (2004), Yoo et al. (2005), Grob et al. (2006), Borsch et al. (2007), Löhne et al. (2007), Borsch et al. (2008), Löhne et al. (2008), Nixon (2008), D. W. Taylor (2008), M. L. Taylor et al. (2008), P. A. Volkova and Shipunov (2008), and Zhou and Fu (2008), among others.

    Published work on the Nymphaeales is authored by Carlquist et al. (2009), Carlquist and E. L. Schneider (2009), Friis et al. (2009), Hu et al. (2009), J.-K. Li and Huang (2009), Rudall et al. (2009), E. L. Schneider et al. (2009), M. L. Taylor and Williams (2009), Williams et al. (2010), and Yin et al. (2010).

    Contributions to the Nymphaeales Symposium are published in Volume 57, Number 4 of the November 2008 issue of the journal Taxon (Borsch and P. S. Soltis 2008). The perianth biology of Nymphaeales figures prominently in a "Mosaic Theory for the Evolution of the Dimorphic Perianth" (Warner et al. 2009).

    Based on the potential importance of water lilies and their close relatives in understanding the evolution of angiosperms, Cabomba (Nymphaeanae, Nymphaeales, Nymphaeaceae) emerges as a key experimental model basal flowering plant (Vialette-Guiraud et al. 2011), together with Amborella and Persea.

    Hydatellaceae regarded by Cronquist (1981) as advanced commelinid monocots now occupy a basal position together with extant ANITA grade dicots (Rudall et al. 2007, Saarela et al. 2007, Friedman 2008, Remizowa et al. 2008, Rudall et al. 2008, Rudall et al. 2009, Sokoloff et al. 2009, Sokoloff et al. 2010, M. L. Taylor et al. 2010, Prychid et al. 2011). According to one review, Hydatellaceae do not shed new light on the enigmatic origins of floral morphology (P. S. Soltis et al. 2009).

    Austrobaileyanae. Hao et al. (2000), Carlquist and Schneider (2002), Friedman et al. (2003), Williams and Friedman (2004), Denk and Oh (2005), Lyew et al. (2007), Morris et al. (2007), and Ye Sun et al. (2010) have published results of detailed studies of the Schisandraceae (including Illiciaceae). Work on the paleobotany and pollination biology of Trimeniaceae appears in research published by Bernhardt et al. (2003) and T. Yamada et al. (2008), among others.

    A paleophysiologic approach was used to generate data suggesting that leaves assignable to Lower Cretaceous Austrobaileyales possessed "low gas exchange capacities" (title, Feild et al. 2011). This approach should be applied to older leaf permineralizations and reconciled with findings published by Kevin Boyce, Andy Knoll, and others.

    Finally, I. W. Bailey and Swamy (1949), Endress (1980), Endress (1983), Yamada et al. (2003), Williams and Kennard (2006), and Tobe et al. (2007) report key findings on anatomy, developmental morphology, genetics, and reproductive biology of certain Austrobaileyales.

    Magnolianae. Magnoliids as currently understood consist of four orders: Canellales, Laurales, Magnoliales, and Piperales. Chloranthales are unplaced by Chase and Reveal (2009).

    On the right is a picture of a flower of Degeneria roseiflora (Degeneriaceae, Magnoliales, Magnolianae), and several fragrant flower buds at different stages of maturity. Two of the largest flower buds shown on this kodachrome opened one by one on the next two successive nights, releasing a rose-like fragrance (photographed by the author). Degeneriaceae are related to Winteraceae and Magnoliaceae (A. C. Smith 1981, J. M. Miller 1988, A. C. Smith 1991).

    Molecular phylogenies of the group have been proposed by Azuma (2001) and Sauquet et al. (2003); and additional studies on plastid genes have been published (Y. L. Qiu et al. 1993, Cai et al. 2006).

    Some of the biogeographically and morphologically interesting species and families of magnoliids have been incompletely studied using modern molecular approaches, or not researched at all. More molecular phylogenetic work is needed to clarify relationships of Degeneriaceae and Winteraceae, both with species indigenous to the high islands of the southwest Pacific on geologic rock formations and fossil island arcs (arcs insulaires fossiles) equal in age to New Caledonia (Nouvelle Calédonie) where Amborella trichopoda occurs.

    Complex insect pollinator-plant interactions evidently were in place in Nymphaeaceae during Cretaceous time (Gandolfo et al. 2004). Yet, only a few genera are known from the early Cretaceous Yixian Formation of Asia (and elsewhere in the world among other strata), consisting of fossilized, detached plant parts and flowers, and the fossil remains of other plants classifiable in a couple orders and families (Friis et al. 1997, G. Sun and Dilcher 1997, G. Sun et al. 2001).

    The anatomy, biogeography, ecophysiology, evolutionary history, molecular systematics, phylogenetic relationships, pollination ecology, reproductive biology, and taxonomy of certain magnoliid basal angiosperms is reviewed by I. W. Bailey and A. C. Smith (1942), I. W. Bailey and Swamy (1951), Canright (1952), Endress (1984), Friis et al. (1986), Bernhardt and Thien (1987), Carlquist (1987), Endress and Hufford (1989), J. M. Miller (1989), Pellmyr et al. (1990), Loconte and Stevenson (1991), Endress (1994), Crane et al. (1994), Carlquist (1996), Friis et al. (1997), Friis et al. (2000), T. N. Taylor et al. (pages 904-917, Chapter 22, 2009), Saunders (2010), and Feild et al. (2011), among others.

    Magnoliales. Basic research on magnoliids is authored by Allouche et al. (2009), Goodrich and Raguso (2009), Lora et al. (2009), Marquínez et al. (2009), Oelschlägel et al. (2009), Rohwer et al. (2009), Staedler and Endress (2009), Su and Saunders (2009), Tamaki et al. (2009), Oppel and Mack (2010), Z.-H. Wang et al. (2010), X. M. Zhang et al. (2010), L. Zhou et al. (2010), Botermans et al. (2011), and Teichert et al. (2011), among others.

    Focused investigations of magnoliid angiosperms include Doust (2001), Endress (2001), Kimoto and Tobe (2001), Sauquet et al. (2003), Cai et al. (2006), Oginuma and Tobe (2006), Xu and Rudall (2006), Buzgo et al. (2007), Staedler et al. (2007), Wanke et al. (2007), Couvreur et al. (2008, two papers), Gamerro and Barreda (2008), García-González et al. (2008), Kimoto and Tobe (2008), Madrid and Friedman (2008), Nie et al. (2008), Su et al. (2008), Takahashi et al. (2008), Viehofen et al. (2008), and Watanabe et al. (2008), among others.

    Studies of magnoliids include del C. Jiménez-Pérez and Lorea-Hernández (2009), Liao et al. (2010), Surveswaran et al. (2010), Weerasooriya and R. M. K. Saunders (2010), Xu and Ronse de Craene (two papers, 2010), and Endress and Armstrong (2011), among others.

    Saunders (2010) reviews floral homeotic transformations and morphology of Annonaceae. The study by Saunders complements work on the evo-devo of floral development by Endress and Armstrong (2011).

    Despite many published field and laboratory studies on the basic biology and evolution of magnoliid basal angiosperms (see above citations), the molecular phylogenetic relationships among the component families and genera are unclear. Possibly critical families such as Annonaceae, Degeneriaceae, Magnoliaceae, and Winteraceae are incompletely studied from this research perspective (P. S. Soltis et al. 2009).

    Incremental progress has been made in deciphering the tulip tree genome (Liang et al. 2007, Liang et al. 2008, Liang et al. 2011) but more work at the genomic level is needed on other magnoliid timber tree species including degenerias and magnolias.

    Laurales. Several assemblages of rich and diverse Laurales, including Lovellea wintonensis (Dettmann et al. 2009) and Eucalyptolaurus depreii (Coiffard et al. 2009) are known from early to mid-Cretaceous rocks of Australia and Europe, respectively. Occurrence of these derived basal magnoliid angiosperms in sediments of the northern and southern hemisphere before the emergence of New Caledonia from the floor of the Tasman Sea, detract from the idea that Amborella trichopoda is an early divergent, ancestral flowering plant.

    Floral phyllotaxis in early magnoliids was whorled but during the Mesozoic diversification and radiation of the Laurales a transition to spiral phyllotaxis probably occurred (Staedler et al. 2007). The Cenomanian fossil magnoliid Mauldinia exhibited whorled floral phyllotaxis (Drinnan et al. 1990). The marginally preserved fossil blossoms of the magnoliids Araripia, Detrusandra, Jerseyanthus, and Virginianthus exhibit spiral floral phyllotaxis (Staedler et al. 2007).

    Studies on the floral genetics and morphology of avocados, cinnamons, and sassafras (Laurales) are published by Chanderbali et al. (2006), Chanderbali et al. (2008), Chanderbali et al. (2009), P.-C. Liao et al. (2010), and K.-F. Chung et al. (2010), among others. Floral development in Myristicaceae (Magnoliales) has been studied by Xu and Ronse de Craene (2010).

    Looking at the evo-devo of floral development of certain extant species of Laurales from a genomic research perspective, remarkable progress has been made in unraveling the avocado genome (Chanderbali et al. 2008).

    Canella (Magnolianae, Laurales, Canellaceae) is a subject for study of xylem hydraulics and vessel anatomy (Feild et al. 2011).

    A taxonomic rediagnosis of the late Cretaceous palynomorph Rosannia manika by Srivastava and Braman (2010) recovered from eroding Canadian sediments, has implications on possible relationships with Lactoridaceae, an endemic magnoliid to the Juan Fernandez Islands of the South Pacific Ocean.

    Paleobotanical work in Maastrichtian Age beds of New Zealand uncovers mesofossils assignable to Laurales and Podocarpales (Cantrill et al. 2011).

    Piperales. The Piperales, including Chloranthaceae, occupy an evolutionary position between true magnoliids and hamamelids (Crane 1989). Several anatomical, evolutionary developmental, molecular phylogenetic, paleobotanical, and taxonomic studies on members of the Piperales appear in the literature including papers by Carlquist (1987), von Balthazar and Endress (1999), J. A. Doyle et al. (2003), S. Kim et al. (2005), G. S. Li et al. (2005), Arias and Williams (2008), Jaramillo et al. (2008), J. F. Smith et al. (2008), Coe and Bornstein (2009), Horner et al. (2009), and Samain et al. (2009), among others.

    Additional work covering these research perspectives appears in print as original research papers and reviews by Kvaček and Friis (2010), Samain et al. (2010), Antonelli and Sanmartin (2011), and Friis and Pedersen (2011), among others.

    A potentially interesting problem from a coevolutionary perspective is addressed by a paper published by Strutzenberger et al. (2010) having to do with shifting geometrid moth antagonists and Piperales host plant species.

    Fossilized stamens, pollen, and small flowers assignable to Chloranthaceae (Eklund et al. 2004, Friis et al. 2006) have been found in sediments Barremian in Age (late Neocomian Epoch, Early Cretaceous). Extinct Piperaleans including Chloranthaceae are represented in the fossil record as pollen classifiable to certain Asteropollenites, Clavatipollenites hughesii, and Stephanocolpites (Crane 1989), but also includes discovery of Zlatkocarpus from the Cenomanian (Kvaček and Friis 2010).

    Stamens and flowers discovered in several younger rock formations of the Late Cretaceous Period add another layer of evolutionary complexity to magnoliids and basal eudicots, including the Hamamelidae and Trochodendraceae (Crane 1989).

    I cast the available data on the fossil history of magnoliids and certain basal flowering plants into Table 7. Please note that the number in each cell represents the number of species (or genera, as the case may be).

    Unclassified angiosperms. Several fossil genera cannot be classified in any of the known superorders of flowering plants sensu Chase and Reveal (2009). There is little agreement among paleobotanists on how to classify these fossil forms.

    The paleontologic record (in bold type) of these enigmatic fossil flowers and fruits is listed in Table 7 together with basal flowering plants and magnoliids of the angiosperm crown group.


    Table 7. Mesozoic Stratigraphic Distribution of Basal-, Magnoliid-, and Unclassified Angiosperms.

    Order

    Scientific Name and Publication

    Fossilized Remains

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Nymphaeales?

    taxonomy under study (Friis et al. 2001)

    staminate inflorescences and pollen

    0

    ?

    ?

    0

    Laurales

    undescribed (Eklund and Kvaček 1998, Eklund 2000)

    four unnamed flowers

    0

    0

    0

    4?

    Assignment to Superorder in Doubt

    Afrasita lejalnicoliae (Krassilov et al. 2004)

    infructescences

    0

    0

    1

    0

    Piperales

    Anacostia (Friis et al. 1997)

    pollen and fruits

    0

    1

    1

    0

    Assignment to Superorder in Doubt

    Appomattoxia ancistrophora (Friis et al. 1995)

    fruits

    0

    0

    1

    0

    Nymphaeales

    Aquatifolia fluitans (Hongshan Wang and Dilcher 2006)

    leaves

    0

    0

    1

    0

    Assignment in Doubt

    Araripia florifera (Mohr and Eklund 2003)

    flowers

    0

    0

    1

    0

    Magnoliales

    Archaeanthus linnenbergerii (Dilcher and Crane 1985)

    fruit cluster (flowers, bud scales, and leaves described as form genera)

    0

    0

    1

    0

    Assignment in Doubt

    Archaefructus (Sun et al. 1998, 2001)

    flowers and leafy fruiting axes

    0

    2

    0

    0

    Piperales

    Asteropollis (Friis et al. 2000, Eklund et al. 2004)

    palynomorphs inside stamens, staminate inflorescences and pistillate flowers

    0

    1

    0

    0

    Assignment to Superorder in Doubt

    Baasoxylon parenchymatosum (Wheeler and Lehman 2000)

    wood

    0

    0

    0

    1

    Assignment to Superorder in Doubt

    Beipiaoa (Sun et al. 2001)

    fruits

    0

    3

    0

    0

    Nymphaeales

    Brasenites kansense (H. Wang and Dilcher 2006)

    leaves

    0

    0

    1

    0

    Assignment to Superorder in Doubt

    Callianthus dilae (X. Wang and Zheng 2009)

    flower, fruits and pollen

    0

    1

    0

    0

    Assignment to Superorder in Doubt

    Caloda delevoryana (Dilcher and Kovach 1986)

    inflorescence and fruit

    0

    0

    1

    0

    Piperales

    Canrightia resinifera (Friis and Pedersen 2011)

    pollen and flowers

    0

    1

    0

    0

    Austrobaileyales? Nymphaeales?

    Carpestella lacunata (von Balthazar et al. 2008)

    flower

    0

    0

    1

    0

    Piperales

    Chloranthistemon (Crane et al. 1989, Eklund et al. 1997)

    inflorescences and flowers

    0

    0

    0

    >2

    Piperales

    Clavatipollenites (Friis et al. 2000, Eklund et al. 2004)

    palynomorphs inside stamens, staminate inflorescences and pistillate flowers

    0

    1

    0

    0

    Piperales

    Couperites mauldinensis (Pedersen et al. 1991)

    fruits

    0

    0

    1

    0

    Magnoliales? Laurales?

    Cronquistiflora sayrevillensis (Crepet and Nixon 1998)

    flowers and fruits

    0

    0

    1

    0

    Magnoliales? Laurales?

    Detrusandra mystagoga (Crepet and Nixon 1998)

    flowers and fruits

    0

    0

    1

    0

    Magnoliales

    Endressinia brasiliana (Mohr and Bernardes-de-Oliveira 2004)

    flowers

    0

    0

    1

    0

    Magnoliales

    Futabanthus asamigawaensis (Takahashi et al. 2008)

    flower

    0

    0

    0

    1

    Laurales? Magnoliales?

    Hidakanthus (Nishida et al. 1996)

    carpels

    0

    0

    0

    1

    Assignment in Doubt

    Hyrcantha decussata (Friis et al. 2006, Leng and Friis 2006, Dilcher et al. 2007)

    flowers and leaves associated with flowers, infructescences

    0

    0

    1

    0

    Assignment in Doubt

    Hyrcantha karatscheensis (Krassilov et al. 1983)

    inflorescence

    0

    0

    1

    0

    Austrobaileyales

    Illiciospermum (Frumin and Friis 1999)

    seeds

    0

    0

    1

    0

    Laurales

    Jerseyanthus calycanthoides (Crepet et al. 2005)

    flowers, stamens, staminodes, and pollen

    0

    0

    1

    0

    Laurales? Magnoliales?

    Keraocarpon (Ohana et al. 1999)

    fruits

    0

    0

    0

    2

    Magnoliales

    Lactoripollenites africanus (Zavada and Benson 1987)

    palynomorphs

    0

    0

    0

    1

    Laurales

    Lauranthus (Takahashi et al. 2001)

    flower

    0

    0

    0

    1?

    Assignment in Doubt

    Lesqueria elocata (Crane and Dilcher 1984)

    fruiting axis

    0

    0

    1

    0

    Magnoliales

    Liriodendroidea (Knobloch and Mai 1986, Frumin and Friis 1996, 1999)

    pollen and wood

    0

    0

    4

    4

    Magnoliales?

    Litocarpon beardii (Delevoryas and Mickle 1995)

    fruit with follicles

    0

    0

    0

    1

    Laurales

    Mauldinia (Drinnan et al. 1990, Eklund and Kvaček 1998, Frumin et al. 2004, Friis et al. 2006, Viehofen et al. 2008)

    flowers, inflorescences, and gynoecia

    0

    0

    2

    >2

    Assignment to Superorder in Doubt

    Metcalfeoxylon kirtlandense (Wheeler and Lehman 2000)

    wood

    0

    0

    0

    1

    Nymphaeales

    Microvictoria (Gandolfo et al. 2004)

    flowers

    0

    0

    1

    0

    Nymphaeales

    Monetianthus mirus (Friis et al. 2009)

    flower

    0

    0

    1

    0

    Assignment in Doubt

    Myricanthium (Kvacek and Eklund 2003)

    flowers

    0

    0

    2

    0

    Laurales

    Neusenia (Eklund 2000)

    flowers

    0

    0

    0

    1?

    Assignment to Superorder in Doubt

    Noferinia fusicarpa (Lupia et al. 2002)

    flowers

    0

    0

    0

    1

    Assignment to Superorder in Doubt

    Pageoxylon cretaceum (Wheeler and Lehman 2000)

    wood

    0

    0

    0

    1?

    Assignment in Doubt

    Palaeoanthella huangii (Poinar and Chambers 2005)

    flower

    0

    0

    1

    0

    Assignment in Doubt

    Paraphyllanthoxylon anazasii (Wheeler et al. 1995)

    wood

    0

    0

    0

    1

    Laurales

    Perseanthus (Herendeen et al. 1994)

    flower

    0

    0

    1

    0

    Nymphaeales?

    Ploufolia cerciforme (Sender et al. 2010)

    leaves

    0

    0

    1

    0

    Nymphaeales

    Pluricarpellatia peltata (Mohr et al. 2008)

    flowers, inflorescences, leaves, rhizomes, seeds, shoots

    0

    0

    1

    0

    Laurales?

    Pragocladus lauroides (Kvacek and Eklund 2003)

    inflorescences

    0

    0

    1

    0

    Assignment in Doubt

    Prisca reynoldsii (Retallack and Dilcher 1981, Drinnan et al. 1990)

    flowers? inflorescences?

    0

    0

    1

    0

    Assignment in Doubt

    Protomonimia kasai-nakajhongii (Nishida and Nishida 1988)

    carpels and fruits

    0

    0

    1

    0

    Nymphaeales

    Scutifolium jordanicum (D. W. Taylor et al. 2008)

    leaves and axes

    0

    0

    1

    0

    Assignment to Superorder in Doubt

    Silvianthemum suecicum (Friis 1990)

    inflorescence and fruit

    0

    0

    0

    1

    Nymphaeales

    Symphaenale futabensis (Takahashi et al. 2007)

    seeds

    0

    0

    0

    1

    Laurales?

    Virginianthus calycanthoides (Friis et al. 1994)

    flower

    0

    0

    1

    0

    Magnoliales

    Winteroxylon (Poole and Francis 2000)

    wood

    0

    0

    0

    2

    Assignment in Doubt

    Xingxueiana heilongjiangensis (Sun and Dilcher 1997)

    inflorescence

    0

    1

    0

    0

    Piperales

    Zlatkocarpus (Kvaček and Friis 2010)

    fruits, pollen, and one inflorescence

    0

    0

    2

    0


    Minimum age mapping the magnoliids. Fossil history of basal branches of the crown group is unclear and based on scanty paleobotanical evidence (T. N. Taylor et al. 2009, and Table 7). Magnoliids, though appearing above basal flowering plant superorders in molecular phylogenetic reconstructions, might be closer to the putative angiosperm stem than currently understood.

    Crepet et al. (2004) subjected nucleic acid sequence data from selected taxa or groups representing the major basal lineages of flowering plants to cladistic analysis, and mapped minimum ages in millions of years to main branch points where each clade diverged.

    The graphic below is redrawn from Figure 16 of Crepet et al. (2004). Results of the phylogenetic analysis by Crepet et al. (2004) are condensed and display certain orders and families that may be cross-referenced to the APG III phylogram pictured above.

    I colored the taxon and/or group names on the dendrogram so that cross-referencing with the higher order classification of Cronquist (1981) is easy. Magnoliidae are shown with indigo brown type. Hamamelidae are depicted with magenta letters. Monocots are labeled in green, and the Rosidae are colored red. The remainder of the eudicots make-up most of Cronquist's Dilleniidae, Rosidae, and Asteridae comprising the majority of extant flowering plant species.

    The Crepet et al. (2004) minimum age dates on the above dendrogram fall within the Neocomian Epoch of the Early Cretaceous Period that ended about 121 MYA and Gallic Epoch ending at 89 MYA. The remainder of the Late Cretaceous Period is the Senonian Epoch culminating with the K-Pg Event 65 MYA.

    Should Crepet's early attempt to minimum age map basal flowering plants be updated to include the 123-124 million year old eudicot Leefructus (G. Sun et al. 2011)?

    Despite many years of hard work on the plant biology of basal angiosperms of the crown group, the evolution and paleobotany of floral development has "two major problems" (pages 559-560, Endress 2003 [phrase in brackets [] is mine):

  • one, "sepals and petals [in certain basal angiosperms] are not clearly differentiated," and
  • two, "perianth organs often occur in more than two series ... So where does the flower begin? ..."
  • The first problem might be explained by understanding trafficking of certain homeodomain TFs in SAMs of extant basal flowering plants and woody magnoliids. Homeodomain protein trafficking in model eudicots is conserved, often unidirectional, developmentally important, and ontogenetically controlled (J.-Y. Kim et al. 2003).

    A physiology of SAM macromolecular trafficking, when extrapolated to seed plants in deep time is an important component of two prevailing models of cone organization and floral origins (Baum and Hileman 2006, Theißen and Melzer 2007).

    Insight into a possible solution to the second problem quoted above might be gained by mining Paleozoic rocks to find indisputable evidence of bisexual protoflowers predicted by the Theißen and Melzer model during the interval in geologic time (260 to 300 MYA) when protein biochemists and some molecular systematists suggest that angiosperms diverged from the MRCA.

    The Paleozoic fossils Phasmatocycas bridwellii (Axsmith et al. 2003) and Sobernheimia jonkeri (Kerp 1983) among other incompletely diagnosed Permo-Carboniferous gigantopteroids, might be detached megasporophylls of massive bisexual protoflowers.

    Knowledge of carpel, floral, and ovular transcriptional regulators in extant angiosperm model organisms does not preclude derivation of evo-devo models that explain curling, inrolling, and fusion in 300 million year old spermopteroid Phasmatocycas bridwellii leaves to form carpels, ovaries, and pistils.

    The frequency of flowering plant reproductive fossils of core eudicots, magnoliids, ANITA clade orders and families, and monocots increases dramatically by the Albian Age of the Cretaceous Period (Friis et al. 2006).

    Monocots. The following subsections constitute a brief survey of the paleontologic record of superorder Lilianae. The non-commelinid monocots are divided into the Acorales, Alismatales, Asparagales, Dioscoreales, Liliales, Pandanales, and Petrosaviales (Chase and Reveal 2009). I discuss the fossil history of commelinid monocots in a separate section.

    In 1981 Daghlian reported that the Mesozoic fossil record of monocots consisted of Alismataceae, Araceae, Arecaceae, Dioscoreaceae, Pandanaceae, Poaceae, Smilacaceae, and Zingiberaceae. Some of the controversial early records were omitted by Daghlian's early review (1981).

    The fossil history of monocots is reviewed by Stockey (2006) and T. N. Taylor et al. (2009). A compilation of advances in monocot anatomy, evo-devo, and phylogeny is available (Seberg et al. 2010).

    Friis and coworkers (2006) report a spectacular trove of indeterminate monocotyledonous angiosperm palynomorphs, flower casts, and fossilized inflorescences from the Early Cretaceous (Neocomian) of Portugal.

    Jarzen (1983), J. Müller (1984), Dahlgren et al. (1985), Uhl and Dransfield (1987), Friis (1988), Gandolfo et al. (2002), Ramanujam (2004), Friis et al. (2006), Pan et al. (2006), Scherer et al. (2006), and Stockey et al. (2007) are important sources of paleontologic data.

    The image above is the yellow floral variant of Lilium columbianum (Liliaceae, Liliales, Lilianae), which is indigenous to native prairie at the summit of Mary's Peak in the northern Coast Range of western North America.

    Monocot diversity is summarized in Dahlgren and Clifford (1982) and by Dahlgren et al. (1985). Basal monocots are reviewed by Igersheim et al. (2001). A modern synthesis of the evolutionary relationships among monocotyledonous flowering plants is published by Janssen et al. (2004).

    The "evolutionary history of the monocot flower" is published by Remizowa et al. (title, 2011).

    Michelangeli et al. (2003), Chase (2004), Chase et al. (2006), J. A. Doyle et al. (2008), and Nadot et al. (2008) review the phylogenetic relationships of monocots.

    Phylogenetic studies of KNOX genes and homeodomain proteins of extant grasses and eudicots suggest that KNOX Class I and KNOX Class 2 genes diverged prior to the monocot/eudicot split and reflect different evolutionary histories (Bharathan et al. 1999).

    Paula Rudall et al. (2007) provide new insight into the evolution of monocots, including assignment of Hydatellaceae to a basal position in the flowering plant crown group clade. Key studies on the reproductive biology of certain monocots which have a bearing on their adaptive radiation and origin from basal eudicot stock include work by Holloway and Friedman (2008), among others.

    Cibrián-Jaramillo and Martienssen (2009) suggest that evo-devo studies of siRNAs might shed light on divergence of monocots from eudicots.

    Alismatales. Alismatales contain several economic plants used as a source of food (e.g. Sagittaria). Marine species known as eelgrasses are essential components of estuarine habitats occupied by commercially important fish.

    The image to the right is a clump of skunk cabbage (Lysichiton americanum, Araceae, Alismatales, Lilianae), a species indigenous to cool, coastal and montane wetlands of western North America.

    Chromosomal evolution in the Alismatales is reviewed by Feitoza et al. (2009). A second review by Furness and Banks (2010) addresses the topic of pollen evolution of the group.

    Molecular phylogenetic studies of cpDNA sequences by Cuenca et al. (2010) yield new insight into evolution of the Alismatales from the angle of RNA editing, which takes place following transcription of mtDNA.

    A chloroplast phylogeny has been elucidated for certain aroids (Renner et al. 2004), implicating Tertiary floristic links between east Africa, Asia, and North America. Nie et al. (2006) and Mardanov et al. (2008) offer additional insight into the evolution of aroids.

    Asparagales. A molecular phylogenetic study of several plastid and nuclear genes by Joo-Hwan Kim et al. (2010) clarifies relationships among the families of the group.

    The image to the left is a fruiting branch of Asparagus sprengeri (Asparagaceae, Asparagales, Lilianae) photographed in cultivation.

    While Paleogene and Neogene paleobotany is outside the scope of this essay, leaf cuticle studies of Miocene Asteliaceae are important first steps in calibrating phylogenies of Asparagales and related orders of monocots with roots extending back in time to the Late Cretaceous Period (Maciunas et al. 2011).

    Liliales and orchids. Records of Mesozoic fossils referable to the order Liliales consist mainly of palynomorphs deposited in sediments (J. Muller 1981). The fossil history of orchids is cloudy, but Cronquist (1981) suggests an origin of the group from lilies.

    On the right side of the page is an image of Calochortus tolmiei (Liliaceae, Liliales, Lilianae) photographed by the author in 1977 while traveling in western North America.

    Lily flowers express AP1-like MIKC-type MADS-box genes (M.-K. Chen et al. 2008).

    A study by Ramírez et al. (2007) sheds light on the time of origin of a specific orchid and its pollinator with implications toward the phylogeny and origin of monocots. In follow-up work Ramírez et al. (2011) explore peculiar asymmetries in bee and orchid pollination mutualisms possibly involving sensory behaviour.

    Based on a possibility that insect "sensory bias" might affect co-diversification with plant hosts (abstract, Ramírez et al. 2011), could studies of insect pollinator and flowering plant mutualisms from research perspectives of horizontal transmission of tool kit transposable elements shed light on underlying "evolutionary processes" in pollination ecology?

    Commelinid monocots. According to APG III (Chase and Reveal 2009), commelinid monocots consist of four orders (Arecales, Commelinales, Poales, Zingiberales) and one unplaced family (Dasypogonaceae).

    Several molecular phylogenetic studies of the commelinid plastome offer valuable insight on the matter of deep level evolutionary relationships of the group in relation to other monocots (Givnish et al. 2011), among others.

    The picture to the left is a flower of Strelitzia nicolai (Strelitziaceae, Commelinales, Lilianae) from The University of the South Pacific Botanical Garden, Suva, Fiji (photographed by the author in 1988).

    Arecales. The order Arecales contains several economically important palms used as a source of fiber (copra), food, and oil (Cocos nucifera, Elaeis guineensis, Copernicia, among others).

    A review of fossil palms of India is available (Ramanujam 2004). Additional details on the fossil history of certain palm groups may be gleaned from Uhl and Dransfield (1987). Fossil pollen belonging to this subclass may be found in sediments as old as the early Cretaceous Period.

    Remains of fossilized palms, specifically seeds and preserved stems not unlike Sabalites ungeri, are associated with bone permineralizations of immature dinosaurians in the Upper Cretaceous Aguja Formation of southwestern North America (Manchester et al. 2010).

    Students of fossil palms should be cautioned that an early (Late Jurassic) record of Palmoxylon pristina and Palmoxylon simperi (Tidwell et al. 1970) is in doubt. The petrified log fragments in question probably eroded from overlying Paleogene rocks.

    A taphonomic study of fossil palms is available (Marmi et al. 2010). Upper Cretaceous records of palm fruits are known for the genus Nypa (El-Soughier et al. 2011). The aforementioned studies do not obviate the possibility that palm permineralizations will be discovered in Malm rocks.

    Poales. Members of the order Poales are among the most economically important plants known. The major cereal grains of the Poales are oats (Avena), bamboo (Bambusa), rye (Elymus), barley (Hordeum), rice (Oryza), millet (Sorghum), and wheat (Triticum).

    A clump of Joinvillea plicata (Joinvilleaceae, Poales, Lilianae) indigenous to Viti Levu Island of the South Pacific Ocean is pictured to the right. Saula Vodonaivalu, Curator Emeritus of the South Pacific Regional Herbarium, University of the South Pacific, is standing next to the plant (photographed by the author).

    Joinvilleaceae are monocotyledonous flowering plants (Tomlinson and A. C. Smith 1970) that share vegetative morphology reminiscent of the enigmatic and controversial Triassic fossil Sanmiguelia lewisii. Joinvilleas possess a primitive morphotype with perfect and complete flowers having petals, sepals, stamens, and a trilocular ovary. Joinvilleaceae are classified by some botanists in Flagellariaceae which is allied to Restionaceae, comprised of Czaja's primary monocots.

    A draft analysis of the cpDNA plastome for Joinvillea plicata is available (Leseberg and Duvall 2009).

    Hydatellaceae (Rudall et al. 2007), a family classified by Cronquist (1981) in the Commelinidae, are discussed in the section on basal angiosperms.

    Kåre Bremer (2002) and Linder et al. (2007) are two key articles on the Mesozoic fossil history and biogeography of commelinid monocots. Whipple et al. (2007) offer important insight on the origin of grasses and the grass lodicule from studies of MIKC-type MADS-box B gene expression of Joinvilleaceae, Streptochaeta angustifolia, a basal grass species, and several derived taxa of Poaceae.

    The molecular systematics of bamboos and related genera of Poaceae is published in a paper by Hisamoto et al. (2008). MIKC-type MADS-box gene expression and evolution in grasses is addressed in papers by Preston and Kellogg (2007) and Preston et al. (2009), among others. Based on detailed genomic studies of Sorghum bicolor, paleopolyploidy about 70 MYA preceded divergence of the millet and rice clades (Paterson et al. 2009).

    Fossil restionaceous pollen has been reported from late Cretaceous sediments (Dahlgren and Clifford 1982). Roots of the Poales, discernable from widespread occurrences of Graminidites (Poales incertae cedis) in dinosaur coprolites and sediments, are traceable to the Maastrichtian Age (Srivastava 2011).

    Zingiberales. The order Zingiberales contains several economically important plants including bananas, ginger, and pineapple.

    The image the left is an inflorescence of a ginger plant Zingiber zerumbet, an aboriginal introduction to the high islands of the South Pacific (photographed by the author).

    Floral tool kit plant biology of gingers and related monocots is an ongoing topic of gene expression research by Chelsea Specht and coworkers (Bartlett and Specht 2010).

    The fossil history of bananas (Musa) is discussed by Manchester and Kress (1993). Bromeliad biogeography and phylogenetics is summarized by Givnish et al. (2004). Floral development of the Zingiberales is reviewed by Kirchoff et al. (2009).

    Gingers are host plants for certain hispine beetles. Ichnofossils allow paleobiologists to infer the existence of extinct phytophagous hispine beetles (García-Robledo and Staines 2008). Wilf et al. (2000) review the fossil history of zingiberids and rolled leaf hispine beetles.

    Table 8 is the Mesozoic fossil record of monocots (superorder Lilianae). Neocomian records for monocots are among the oldest known angiosperm megafossils (T. N. Taylor et al. 2009) paralleling the situation seen in basal angiosperms and magnoliids suggesting unresolved deep divergences.


    Table 8. Mesozoic Stratigraphic Distribution of Monocots.

    Order

    Scientific Name and Publication

    Fossilized Remains

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Arales

    Cobbania corrugata (Stockey et al. 2007)

    whole plants, stems, leaves, roots

    0

    0

    0

    1

    Liliales?

    Cretovarium (Stopes and Fujii 1910)

    flower

    0

    0

    0

    1

    Arecales

    Deccananthus savitrii (Chitaley and Kate 1974)

    flowers and fruits

    0

    0

    0

    1

    Poales

    Graminidites (Srivastava 2011)

    pollen

    0

    0

    0

    1

    Triuridales

    Mabelia archaia (Gandolfo et al. 2002)

    flower

    0

    0

    1

    0

    Triuridales

    Mabelia connatifila (Gandolfo et al. 2002)

    flower

    0

    0

    1

    0

    Arales

    Mayoa portugallica (Friis et al. 2004)

    inflorescence axis with pollen

    0

    1

    0

    0

    Arecales

    Mauritiidites (Herngreen et al. 1996)

    pollen

    0

    0

    0

    1

    Zingiberales

    Musa cardiosperma (Jain 1963)

    fruits and seeds

    0

    0

    0

    1

    Triuridales

    Nuhliantha nyanziana (Gandolfo et al. 2002)

    male flower

    0

    0

    1

    0

    Arecales

    Nypa burtinii (El-Soughier et al. 2011)

    fruits and seeds

    0

    0

    0

    1

    Arecales

    Palmoxylon cliffwoodensis (Daghlian 1981)

    wood

    0

    0

    0

    1

    Arecales

    Pandanites (Scherer et al. 2006)

    pollen

    0

    0

    0

    1

    Arecales

    Pandanus (Jarzen 1983)

    pollen

    0

    0

    0

    >1?

    Alismatales

    Pennipollis (Penny 1988, Hughes 1994)

    palynomorphs

    0

    1

    0

    0

    Alismatales

    Pennistemon (Friis et al. 2000)

    inflorescences with pollen

    0

    1

    0

    0

    Arecales

    Sabal bigbendense (Manchester et al. 2010)

    seeds and stems

    0

    0

    0

    1

    Arecales

    Sabal bracknellense (Manchester et al. 2010)

    seeds and stems

    0

    0

    0

    1

    Arecales

    Sabalites longirhachis (Marmi et al. 2010)

    leaves, roots, stems

    0

    0

    0

    1

    Arecales? Pandanales?

    Shuklanthus superbum (Verma 1958)

    flowers and fruits

    0

    0

    0

    1

    Arecales

    Spinozonocolpites (Herngreen et al. 1996)

    pollen

    0

    0

    0

    1

    Zingiberales

    Spirematospermum chandlerae (Friis 1988)

    fruits, seed

    0

    0

    0

    1

    Arecales? Pandanales?

    Tricoccites trigonum (Chitaley 1956)

    flowers and fruits

    0

    0

    0

    1

    Arecales? Pandanales?

    Viracarpon (Nambudiri and Tidwell 1978)

    flowers and fruits

    0

    0

    0

    1


    Eudicots. Eudicots assignable to the Ranunculanae are traceable to the Barremian Age (Neocomian Epoch) of the Lower Cretaceous Period (G. Sun et al. 2011).

    Eudicots consist of superorder Buxanae (a single order Buxales), superorder Proteanae (one order, Proteales), and superorder Ranunculanae consisting of the Ranunculales. Superorder Trochodendranae (comprised of the order Trochodendrales) is somehow left out of the paper by Chase and Reveal, but is clearly intended (page 125, Figure 1, 2009).

    Superorder Trochodendranae Takhtajan ex Reveal, Phytologia 79(2): 71, 29 Aug 1995, is a valid name (Reveal 1995). Superorder Ceratophyllanae and its only order Ceratophyllales are sister to the eudicots and unplaced (Chase and Reveal 2009).

    The evolutionary history, flower structure, fossil history, and phylogenetic relationships of eudicots, core eudicots, and Ceratophyllanae, among other groups, is reviewed by Drinnan et al. (1994), D. E. Soltis et al. (2003), Judd and Olmstead (2004), Magallón (2004), L. Chen et al. (2007), Worberg et al. (2007), Dilcher and H. Wang (2009), Gomez et al. (2009), W. Wang et al. (2009), and Endress (2010), among others.

    The kodachrome to the right is the lower eudicot Adonis amurensis (Ranunculaceae, Ranunculales, Ranunculanae) photographed by the author.

    Key phylogenetic and evo-devo studies of eudicots are published by Hoot et al. (1999), Magallón et al. (1999), Fishbein et al. (2001), D. E. Soltis et al. (2003), Chaw et al. (2004), S. Kim et al. (2004), R.-Q. Li (2004), C. L. Anderson et al. (2005), Zahn et al. (2005), De Bodt et al. (2006), Endress and Mathews (2006), Barakat et al. (2007), Ren et al. (2007), Ronse De Craene (2007), Hilu et al. (2008), Ronse De Craene (2008), Endress (2010), and Yellina et al. (2010), among others.

    A supposed "unidirectional model of ovary position evolution" is called into question by an elegant phylogenetic study that incorporates developmental data (page S252, D. E. Soltis et al. 2003). Endress (2010) proposes changes to the classification of major eudicot groups based on ovular features specifically of the nucellar type.

    Phylogenetic analyses of the AP1/FUL gene lineage in flowering plants by Litt and Irish (2003) suggest that a gene duplication coincides with diversification and radiation within the ranunculid lineage. Further, Litt and Irish propose that one or more gene duplications in the AP1 MIKC-type MADS-box gene lineage leading to the euAP1 clade might have played a role in the evolution of eudicot floral structure.

    Some of the high points on floral evo-devo of eudicots with bearing on the greater question of the timing of the origin of floral organs are published in recent works by Hileman and Irish (2009), Korotkova et al. (2009), Rasmussen et al. (2009), Endress (2010), C. Liu et al. (2010), and Bharti Sharma et al. (2011).

    Evolutionary development and phylogeny of the AP3/TM6 gene lineage in eudicots is reviewed by Hileman and Irish (2009). Conclusions reached by Bharti Sharma et al. (2011) on evo-devo studies of paralogs of AP3 in Aquilegia suggest that:

    "... the AqAP3-3 lineage underwent progressive subfunctionalization within the order Ranunculales, ultimately yielding a specific role in petal identity that has probably been conserved, in stark contrast with the multiple independent origins predicted by botanical theories."

    The above statement is from the abstract of Bharti Sharma, C. Guo, H. Kong, and E. M. Kramer, (2011), Petal-specific subfunctionalization of an AP3 paralog in the Ranunculales and its implications for petal evolution. New Phytologist 191(3): 870-883.

    Zahn et al. (2005) report several MIKC-type MADS-box E gene duplications within the AGL2, AGL3, AGL4, and AGL9 molecular clades of the eudicot lineage, including the branch leading to monocots. Duplications of the TCP family of genes, specifically CYC, predate divergence of core eudicots (Howarth and Donoghue 2006).

    Buxanae. The Mesozoic fossil history of the eudicot order Buxales is reviewed by T. N. Taylor et al. (2009).

    Buxales and other fossil eudicots figure prominently in studies on Cretaceous extinctions (Heimhofer et al. 2005) and phylogenetics (C. L. Anderson et al. 2005).

    Ceratophyllanae. Once classified as magnoliids (Cronquist 1981), Ceratophyllanae are represented in the Mesozoic fossil record by Donlesia dakotensis from the North American Dakota Formation (Dilcher and H. Wang 2009).

    Proteanae. Proteas are now included with platanoids (T. N. Taylor et al. 2009) and Nelumbonaceae (Gandolfo and Cuneo 2005) in the order Proteales. Fossil Protea pollen are known from the subantarctic islands (Wanntorp et al. 2011).

    Platanoids (sycamores and relatives) have a rich Cretaceous fossil history (Upchurch and Wolfe 1987, Friis et al. 1988, Crane et al. 1993, Magallón-Puebla et al. 1997, Upchurch and Wolfe 1987, Mindell et al. 2006, Maslova 2010, Golovneva 2010, H. Wang et al. 2011, among others).

    The foliage genus Sapindopsis (Hickey and J. A. Doyle 1977) is one of the best known examples of late Mesozoic platanoid foliage (T. N. Taylor et al. 2009). Permineralized Cretaceous woods, Icacinoxylon and Plataninium (Wheeler and Lehman 2000, Oakley and Falcon-Lang 2009), might belong to extinct Proteales but anatomical connections with detached foliage, flowers, and fruits are lacking.

    A new classification system of fossil platanoids is proposed by Maslova (2010), which is at variance with the older APG II classification scheme. Surprisingly, Maslova (2010) neglects to compare these novel ideas with the more recent APG III system (Chase and Reveal 2009).

    Ranunculanae. The Mesozoic fossil history of the eudicot order Ranunculales is reviewed by Krassilov (1997), Krassilov and Golovneva (2001), Krassilov and Golovneva (2004), von Balthazar et al. (2005), Gomez et al. (2009), and T. N. Taylor et al. (2009), among others.

    The oldest fossil ranunculid eudicot, Leefructus, is 123 to 124 million years old, which is the Barremian Age of the Lower Cretaceous Period (G. Sun et al. 2011).

    On the left side of the page is an image of Platystemon californicus (Papaveraceae, Papaverales, Ranunculanae) photographed by the author in the 1970s while traveling in western North America. Does the flower in the center of the image belong to the same plant?

    Perianth evolution in Ranunculales is discussed in a study by Rasmussen et al. (2009). The genus Aquilegia (Ranunculaceae, Ranunculales, Ranunculanae) has become a model organism for floral organ evo-devo (Kramer 2009, Bharti Sharma et al. 2011).

    Trochodendranae. Cretaceous fossils referable to the Trochodendrales are described by Crane (1989). The paleontology of the group is summarized in T. N. Taylor et al. (2009).

    I cast the available data on the fossil history of eudicots (excluding core eudicots) and Ceratophyllanae into Table 9. Please note that the number in each cell represents the number of species or genera as the case may be.


    Table 9. Mesozoic Stratigraphic Distribution of Eudicots and Ceratophyllanae (Except Core Eudicots).

    Order

    Scientific Name and Publication

    Fossilized Remains

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Proteales

    undescribed (Dettmann and Jarzen 1998)

    pollen

    0

    0

    0

    >2?

    Proteales

    unclassified platanoid leaves and fertile structures (Upchurch and Wolfe 1987, Mindell et al. 2006)

    leaves, flowers, and inflorescences

    0

    0

    >2

    >2

    Proteales

    Nelumbonaceae under study (Gandolfo and Cuneo 2005)

    leaves and detached fruits

    0

    0

    0

    1

    Trochodendrales

    unclassified leaves (Upchurch and Wolfe 1987)

    leaves

    0

    0

    >2

    >2

    Assignment in Doubt

    Allonia decandra (Magallón-Puebla et al. 1996)

    flower

    0

    0

    0

    1

    Proteales

    Beaupreaidites (Wanntorp et al. 2011)

    pollen

    0

    0

    0

    1

    Ranunculales

    Callicrypta chlamydea (Krassilov and Golovneva 2004)

    flowers

    0

    0

    1

    0

    Ranunculales?

    Caspiocarpus paniculiger (Krassilov 1997)

    flowers

    0

    0

    1

    0

    Ceratophyllales

    Donlesia dakotensis (Dilcher and H. Wang 2009)

    fruits

    0

    0

    1

    0

    Proteales

    Exnelumbites callejasiae (Estrada-Ruiz et al. 2011)

    leaves

    0

    0

    0

    1

    Ranunculales

    Freyantha sibirica (Krassilov and Golovneva 2001)

    staminate inflorescence and flowers

    0

    0

    1

    0

    Trochodendrales

    Joffrea (Crane 1989)

    leaves and winged fruits

    0

    0

    0

    >2

    Ranunculales?

    Klitzschphyllites choffatii (Gomez et al. 2009)

    leaves

    0

    0

    1

    0

    Ranunculales

    Leefructus (G. Sun et al. 2011)

    inflorescences and leaves

    0

    1

    0

    0

    Ranunculales

    Macclintockia (Moiseva 2011)

    leaves

    0

    0

    0

    3

    Trochodendrales

    Nordenskioldia (Crane 1989)

    leaves, inflorescences, fruits, and fruitlets, shoots

    0

    0

    0

    1

    Assignment in Doubt

    Normanthus (Schönenberger et al. 2001, Friis et al. 2003)

    inflorescence

    0

    0

    1

    0

    Proteales

    Paraprotophyllum (Golovneva 2010)

    leaves

    0

    0

    1

    0

    Proteales

    Platananthus (Friis et al. 1988)

    inflorescence

    0

    0

    1

    0

    Proteales

    Platanocarpus brookensis (Crane et al. 1993)

    pistillate inflorescences and infructescences

    0

    0

    1

    0

    Proteales

    Platanocarpus marylandensis (Friis et al. 1988)

    flowers and fruits

    0

    0

    1

    0

    Proteales

    Proteacidites (Wanntorp et al. 2011)

    pollen

    0

    0

    0

    2

    Proteales

    Quadriplatanus georgianus (Magallón-Puebla et al. 1997)

    staminate and pistillate flowers

    0

    0

    0

    1

    Ranunculales

    Sagaria cilentana (Bravi et al. 2010)

    inflorescence

    0

    0

    1

    0

    Proteales

    Sapindopsis (Hickey and J. A. Doyle 1977)

    leaves

    0

    0

    >2

    >2

    Ranunculales

    Teixeiraea lusitanica (von Balthazar et al. 2005)

    male flower, flower buds, and pollen

    0

    0

    1

    0


    Core eudicots, rosids, and asterids. According to APG III (2009) core eudicots are comprised of superorder Myrothamnanae consisting of a single order Gunnerales, the unplaced order Saxifragales, superorder Rosanae (many rosid orders and families of fabids and malvids) and the enigmatic Vitales, and the unplaced family Dilleniaceae. The latest phylogenetic analysis of this group suggests that "both superrosids and superasterids arose in as little as five million years," during the Cretaceous Period (abstract, Moore et al. 2010).

    In addition, core eudicots include superorder Berberidopsidanae (the single order Berberidopsidales), superorder Caryophyllanae (one order, Caryophyllales), superorder Santalanae consisting of the order Santalales and several asterid, campanulid, and lamiid orders classified in the superorder Asteranae (Chase and Reveal 2009).

    During the Cretaceous Period certain core eudicots were important floristic elements in many localities as judged from the common occurrence of Normapollis. Albian compression floras contain a high frequency of platanoid leaves and definitive leaf-forms which are classifiable to Trochodendrales (Upchurch and Wolfe 1987).

    Rosids (fabids and malvids) and asterids (lamiids and campanulids) are discussed in essay sections separate from the remaining core eudicots.

    Two MIKC-type MADS-box B gene duplications within the core eudicots probably generated the euAP1, euFUL, and core eudicot FUL-like clade. The AP1/FUL gene duplications potentially generated novel C-terminal motifs in euAP1 proteins with new functions possibly leading to fixation of general eudicot floral structure (Litt and Irish 2003) or further diversification (Shan et al. 2007).

    Caryophyllanae. The betalain containing Caryophyllanae (Clement et al. 1994), a possible distinct evolutionary line of core eudicot flowering plants characterized by unique sieve tube plastid anatomy (Behnke 1994) has been reviewed from the perspective of perianth biology (Brockington et al. 2009).

    Molecular systematics of the Caryophyllales is under study including work published by Cuénoud et al. (2002), Brockington et al. (2009), and Brockington et al. (2011), among others.

    The slide to the left is a cluster of inflorescences of a shrub of Eriogonum torreyanum (Polygonaceae, Caryophyllales, Caryophyllanae), a species indigenous to the Harney Basin of western North America, photographed by the author.

    Cevallos-Ferriz et al. (2008) described a permineralized core eudicot infructescence from the late Cretaceous (Campanian) Cerro del Pueblo Formation of Mexico, which is assignable to Phytolaccaceae.

    Myrothamnanae. The genus Gunnera (Gunnerales) is represented in the Cretaceous record of angiosperms by an extensive pollen record (Jarzen 1980). Placement of Gunnerales by D. E. Soltis et al. (page 466, 2003) "as sister to all other eudicots has important implications for floral evolution."

    Santalanae. Several flowering plant families are parasitic on other vascular plants. Among these Misodendraceae of the order Santalales appeared in aerial canopies of Cretaceous forests some 80 MYA (Vidal-Russell and Nickrent 2008).

    Santalales are represented in the fossil record of Cretaceous woods represented by Agujoxylon olacaceoides (Wheeler and Lehman 2000). Thomas N. Taylor et al. (2009) reviews the paleontologic record of sandalwoods and relatives in the Santalales.

    Saxifragales. Roots of the unplaced core eudicot order Saxifragales may be traced back to the Cretaceous Period (T. N. Taylor et al. 2009). Mesozoic fossil forms are Dewalquea pulchella (Nichols and Jacobson 1982), Aquia brookensis (Crane et al. 1993), Androdecidua endressii (Magallón et al. 2001), and Microaltingia apocarpela (Zhou et al. 2001), among others.

    The molecular systematics and ancient radiations of Saxifragales is resolved in a paper by Jian et al. (2008).

    On the right side of the page is an image of Saxifraga retusa (Saxifragaceae, Saxifragales, unplaced core eudicot) photographed by the author in the 1991 while visiting the University of British Columbia Botanical Garden.

    Table 10 outlines the Mesozoic stratigraphic record of fossil core eudicots and unplaced orders (except rosids and asterids).


    Table 10. Mesozoic Stratigraphic Distribution of Core Eudicots and Unplaced Orders (Except Rosids and Asterids).

    Order

    Scientific Name and Publication

    Fossilized Remains

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Santalales

    Agujoxylon olacaceoides (Wheeler and Lehman 2000)

    wood

    0

    0

    0

    1

    Saxifragales

    Androdecidua endressii (Magallón et al. 2001)

    floral fragments with stamens

    0

    0

    0

    1

    Saxifragales

    Aquia brookensis (Crane et al. 1993)

    staminate inflorescences

    0

    0

    1

    0

    Caryophyllales

    Archaeamphora longicervia (H. Li 2005)

    plant fragments

    0

    0

    0

    1

    Caryophyllales

    Coahuilacarpon phytolaccoides (Cevallos-Ferriz et al. 2008)

    infructescence

    0

    0

    0

    1

    Saxifragales

    Dewalquea pulchella (Nichols and Jacobson 1982)

    leaves

    0

    0

    1

    0

    Gunnerales

    Gunnera (Jarzen 1980)

    pollen

    0

    0

    1

    1

    Saxifragales

    Hamatia (Pederson et al. 1994)

    flower and inflorescence

    0

    0

    1

    0

    Saxifragales

    Microaltingia apocarpela (Zhou et al. 2001)

    pistillate inflorescences and infructescences

    0

    0

    1

    0

    Saxifragales

    Tarahumara (Hernandez-Castillo and Cevallos-Ferriz 1999)

    inflorescence

    0

    0

    0

    1


    Rosanae. Superorder Rosanae consists of the malvid and fabid clades of rosids and the order Vitales (Chase and Reveal 2009). The extant model seed plant species Arabidopsis thaliana and Carica papaya are probably the two best studied malvids from the standpoint of developmental genetics.

    Using fossil calibration points the molecular phylogenetic paper by Beilstein et al. (2010) suggests a Miocene origin of Arabidopsis thaliana and an uppermost Cretaceous origin of the Brassicales. Coevolution of mustards and pierid butterflies first proposed by Ehrlich and Raven (1964) is demonstrable (Beilstein et al. 2010).

    Crepet (1996) offers an insightful review of the tricolpates (tricolpate is a word describing palynomorphs with three furrows [colpae]), many (not all flowering plants with tricolpate pollen are rosids) are now known to be rosids.

    The kodachrome to the left is a flowering branch of a shrub of Sophora formosa (Fabaceae, Fabales, Rosanae) from the Pinaleño Mountains of southwestern North America (photographed by the author).

    Advances in our understanding of Cretaceous rosid phylogeny and radiation appear in work published by Sytsma et al. (2002), Hall et al. (2004), Wojciechowski et al. (2004), Davis et al. (2005), L.-B. Zhang (2006), X.-Y. Zhu et al. (2007), Jian et al. (2008), Bello et al. (2009), and Hengchang Wang et al. (2009), among others.

    Robert Jansen et al. (2011) report numerous transfers of rpl22, a plastidic sequence, to the nuclear genomes of several rosids.

    Volume 260, Numbers 2-4 of Plant Systematics and Evolution (2006) is devoted to a review of the evolution, fossil history, morphology, and phylogenetic relationships of rosids. Specific papers in Numbers 2-4 of Volume 260 of possible interest are by von Balthazar et al. (2006), Endress and Friis (2006), Endress and Mathews (2006), Hermsen et al. (2006), Mathews and Endress (2006), and Schönenberger and von Balthazar (2006), among others.

    Malvids. Plant biologists who study angiosperms from biochemical, evo-devo, and genomic research perspectives are probably most familiar with Arabidopsis thaliana, Populus trichocarpa, and Theobroma cacao, which are classified as malvids according to APG III.

    On the right side of the page is an image of Hibiscus hirtus (Malvaceae, Malvales, Rosanae) photographed in cultivation by the author in 1985.

    De Bodt et al. (2006) studied MIKC-type MADS-box gene expression analysis and compared the promoter sequences of two malvid species, Arabidopsis thaliana and Populus trichocarpa, using phylogenetic methods. While the analysis by De Bodt et al. (2006) has no direct bearing on the origin of angiosperms (this was not the intent of their research project) it reveals that TF binding sites of these two eudicots have diverged widely, probably due to gene duplications, loss of function of certain duplicated genes to form pseudogenes, mutations, or isoform genesis.

    Table 11 outlines the Mesozoic stratigraphic distribution of the malvid clade of rosids.


    Table 11. Mesozoic Stratigraphic Distribution of the Malvid Clade of Rosids.

    Order

    Scientific Name and Publication

    Fossilized Remains

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Malvales

    Bombacoxylon langstoni (Wheeler and Lehman 2000)

    wood

    0

    0

    0

    1

    Brassicales

    Dressiantha bicarpellata (Gandolfo et al. 1998)

    flowers

    0

    0

    1

    0

    Assignment in Doubt

    Elsemaria kokubunii (Nishida 1994)

    fruit

    0

    0

    0

    1

    Myrtales

    Esquieria (Friis et al. 1992, Takahashi et al. 1999)

    flowers

    0

    0

    0

    2

    Malvales

    Javelinoxylon multiporosum (Wheeler et al. 1994)

    wood

    0

    0

    0

    1

    Geraniales

    Sarysua pomona (Krassilov et al. 1983)

    inflorescence

    0

    0

    1

    0

    Myrtales

    Trapago angulata (Stockey and Rothwell 1997)

    flower and fruit

    0

    0

    0

    1


    Fabids. The fossil history and phylogenetic systematics of fabids is discussed by Manchester (1987), Donoghue and J. A. Doyle (1989), Crepet et al. (1992), Chen et al. (1999), Zhou et al. (2001) and Takahashi et al. (2008), among others.

    Witch hazels, sweet gums, wax myrtles, beeches, alders, oaks, and beefwoods once classified by Cronquist (1981) in subclass Hamamelidae, and Celastrales, are now placed in the fabid clade of superorder Rosanae together with Fabales and Rosales (Chase and Reveal 2009).

    On the left side of the page is an image of Cercocarpus betuloides (Rosaceae, Rosales, Rosanae) photographed by the author in 1976 while traveling in western North America.

    Some of the best known examples of fossil flowers (see the images at the beginning of this essay and below) are casts and three-dimensional petrifactions of rosids from the Lower Cretaceous Dakota Formation Rose Creek locality. Many of these fossil flowers were comparatively large and pentamerous, possibly allied with the Celastrales (Basinger and Dilcher 1984).

    Several problematic morphotype genera of detached leaves and pollen from the Maastrichtian Age possibly belonging to fabids are reported in the literature (Manchester 1987, among others). According to Friis et al. (2006), Normapolles pollen have been found in situ in several fossilized flowers of primitive beeches and oaks.

    The sandstone cast pictured on the right hand side of this page is an indeterminate pentamerous rosid flower (Celastrales, Rosanae) collected by Professor David L. Dilcher from the Lower Cretaceous Dakota Formation of North America. The image was captured in 1981 while the author was visiting Indiana University.

    Phylogenetic relationships within extant genera classified in the birch family (Betulaceae) ascertained from studies of rbcL, ITS, and morphology are congruent with paleobotanical and paleoecological data (Chen et al. 1999).

    Based on studies of two nuclear- and ten plastid gene loci by S.-D. Zhang et al. (2011) the Rosales are probably monophyletic. Paleobotanical calibration of molecular phylogenetic analyses of rosids and other eudicots are needed especially in view of the rich and diverse fossil record of the group.

    Woody, often tree-like fabids, malvids and other rosids were evidently common in Cretaceous floras including evolutionary lines leading to Paleogene and Neogene species of beeches (including Nothofagus, a favorite of biogeographers), birches, hazelnuts, oaks, and walnuts (Friis et al. 2006, Manos et al. 2007, Golovneva 2008, Narita et al. 2008, Oh and Manos 2008, Tschan et al. 2008, X. Wang 2008, Y.-H. Wang et al. 2009, among others).

    Table 12 outlines the Mesozoic fossil history, at least of definitive reproductive remains of the fabid clade of rosids.


    Table 12. Mesozoic Stratigraphic Distribution of the Fabid Clade of Rosids.

    Order

    Scientific Name and Publication

    Fossilized Remains

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Assignment in Doubt

    undescribed rosids (Herendeen et al. 1999)

    indeterminate flowers and fruits

    0

    0

    0

    >2?

    Rosales

    undescribed rosid (Crepet and Nixon 1996)

    stamens

    0

    0

    1

    0

    Assignment in Doubt

    undescribed rosids (Takahashi et al. 1999)

    indeterminate flowers and fruits

    0

    0

    0

    >2?

    Malpighiales?

    Agapitocarpus (Leng et al. 2005)

    fruits

    0

    0

    0

    1

    Fagales

    Alnipollenites (Miki 1977)

    palynomorphs

    0

    0

    0

    1

    Fagales

    Antiquacupula (Herendeen et al. 1995, Sims et al. 1998)

    flowers and inflorescences

    0

    0

    0

    1

    Fagales

    Antiquocarya (Friis 1983)

    fruits

    0

    0

    0

    1

    Assignment in Doubt

    Aquacarpus hirsutus (Raunsgaard-Pedersen et al. 2007)

    pistillate floral fragments

    0

    0

    1

    0

    Fagales

    Archaefagacea futabensis (Takahashi et al. 2008)

    flower, fruit, pollen

    0

    0

    0

    1

    Fagales

    Archamamelis bivalvis (Endress and Friis 1991)

    flower

    0

    0

    0

    1

    Rosales

    Asterocelastrus cretacea (Krassilov and Pacltova 1989)

    fruits

    0

    0

    1

    0

    Fagales

    Bedellia (Sims et al. 1999)

    flowers and fruits

    0

    0

    0

    1

    Fagales

    Betulaceoipollenites (Miki 1977, X.-J. Sun et al. 1979)

    palynomorphs

    0

    0

    0

    1

    Fagales

    Betulaepollenites (Miki 1977)

    palynomorphs

    0

    0

    0

    1

    Fagales

    Budvaecarpus (Knobloch and Mai 1986)

    flower

    0

    0

    1

    0

    Fagales

    Caryanthus (Friis 1983)

    flowers and fruits

    0

    0

    0

    3

    Assignment in Doubt

    Chitaleypushpam mohgaoense (Paradkar 1973)

    flowers and fruits

    0

    0

    0

    1

    Malpighiales?

    Chontrocarpus (Leng et al. 2005)

    fruits

    0

    0

    0

    1

    Rosales

    Coahuilanthus belindae (Calvillo-Canadell and Cevallos-Ferriz 2007)

    flowers

    0

    0

    0

    1

    Fagales

    Dahlgrenianthus (Friis et al. 2006)

    flowers

    0

    0

    0

    3

    Rosales?

    Divisestylus (Hermsen et al. 2003)

    flowers and fruits

    0

    0

    0

    2

    Fagales

    Endressianthus (Friis et al. 2003)

    staminate inflorescences

    0

    0

    0

    1

    Assignment in Doubt

    Gassonoxylon araliosum (Wheeler and Lehman 2000)

    wood

    0

    0

    0

    1

    Malpighiales

    Lusicarpus planatus (Pedersen et al. 2007)

    pistillate flowers

    0

    0

    1

    0

    Malpighiales

    Lusistemon striatus (Pedersen et al. 2007)

    staminate flower

    0

    0

    1

    0

    Malpighiales?

    Maiandrocarpus (Leng et al. 2005)

    fruits

    0

    0

    0

    1

    Malpighiales?

    Malliocarpus (Leng et al. 2005)

    fruits

    0

    0

    0

    1

    Fagales

    Manningia (Friis 1983, Knobloch and Mai 1986, Friis and Crane 1989)

    flowers and fruits

    0

    0

    0

    1

    Malpighiales?

    Mitocarpus (Leng et al. 2005)

    fruits

    0

    0

    0

    1

    Malpighiales

    Paleoclusia chevalieri (Crepet and Nixon 1998)

    flowers and fruits

    0

    0

    1

    0

    Fagales

    Paraalnipollenites (X.-J. Sun et al. 1979)

    palynomorphs

    0

    0

    0

    1

    Rosales

    Platydiscus peltatus (Schönenberger et al. 2001)

    flower

    0

    0

    0

    1

    Fagales

    Protofagacea allonensis (Herendeen et al. 1995, Sims et al. 1998)

    flowers and inflorescences

    0

    0

    0

    1

    Assignment in Doubt

    Raoanthus intertrappea (Chitaley and Patel 1975)

    flowers and fruits

    0

    0

    0

    1

    Assignment in Doubt

    Silucarpus camptostylus (Pedersen et al. 2007)

    pistillate floral fragments

    0

    0

    1

    0

    Malpighiales

    Spanomera (Drinnan et al. 1991)

    inflorescence, staminate flowers, detached carpels and stamens

    0

    0

    2

    0

    Rosales?

    Tropidogyne pikei (Chambers et al. 2010)

    flower

    0

    0

    1

    0

    Assignment in Doubt

    Tylerianthus crossmanensis (Gandolfo et al. 1998)

    flowers and fruits

    0

    0

    1

    0

    Assignment in Doubt

    Valecarpus petiolatus (Pedersen et al. 2007)

    pistillate floral fragments

    0

    0

    1

    0

    Rosales

    Weinmannioxylon petriella (Poole et al. 2000)

    wood

    0

    0

    0

    1

    Malpighiales?

    Xylocarpus (Leng et al. 2005)

    fruits

    0

    0

    0

    1

    Malpighiales?

    Zeugarocarpus (Leng et al. 2005)

    fruits

    0

    0

    0

    1


    Asteranae. Asterids consists of several campanulid and lamiid orders, and at least five unplaced families (Chase and Reveal 2009). A South American origin of the largest family of asterids (Asteraceae) is suggested by extraordinary fossil finds of preserved capitulae and pollen in Eocene sediments of Patagonia (Barreda et al. 2010).

    The fossil history of asterids is reviewed in a paper by Martínez-Míllan (2010), who concludes that the group may be traced to the late Cretaceous at least 89 MYA.

    The photograph on the right-hand side of the page is Castilleja cinerea (Orobanchaceae, Lamiales, Asteranae) from the San Bernardino Mountains of southwestern North America.

    Kåre Bremer et al. (2004) also present evidence on the Cretaceous radiation of asterids. With the recent find of Burmese amber containing a preserved flower assignable to Cornaceae (Poinar et al. 2007), the fossil history of the group is indisputably older, at least to the Gallic Epoch (Albian Age) of the early Cretaceous Period.

    It is possible that the roots of asterids might lead deep into the Cretaceous stratigraphic record of yet undiscovered woody ancestors resembling modern Rubiaceae such as Guettarda and Psychotria (A. C. Smith and S. P. Darwin 1988).

    Origin of crown group Cornales in the Middle Cretaceous is inferred from molecular phylogenies calibrated by fossils (Xiang et al. 2011). Roots of Alangiaceae may be traced back to the upper Cretaceous (Feng et al. 2009).

    Having more than 13,000 species the Rubiaceae is among the largest families of flowering plants (Cronquist 1981). The fossil history of the family is reviewed by A. Graham (2009) and Martínez-Míllan (2010), among others.

    Leaves of certain rubiads are indistinguishable from Permian gigantopterids in details of cuticles, leaf midrib and petiole anatomy, and venation.

    Molecular phylogenetic studies of cpDNA sequences of the Lamiales shed new light on recent evolution of the group (Schäferhoff et al. 2010). Asteranae continue to be excellent research subjects for ecological and phylogenetic studies of shifting pollinators and the flowers they exploit (P. Wilson et al. 2007, S. D. Smith et al. 2008).

    Review papers and other key evo-devo and phylogenetic studies on asterids, Rubiaceae, and the Ericales clade have been published by Donoghue et al. (1998), Ree and Donoghue (1999), Anderberg et al. (2002), B. Bremer et al. (2002), Schönenberger et al. (2005), B. Bremer (2009), B. Bremer and Eriksson (2009), Howarth and Donoghue (2009), Reardon et al. (2009), and Viaene et al. (2009), among others.

    While work by C.-M. Feng et al. (2011) does not address higher level relationships among asterids, this paper opens a window toward deciphering morphological transitions from combined evo-devo and phylogenetic research perspectives.

    For example, recent gene expression studies of CYC-like genes among genera of plantagos suggest that duplication events in the lineage leading to Plantago caused disintegration of bilateral floral symmetry tool kits resulting in flowers adapted for wind pollination (Preston et al. 2011).

    Table 13 is the Mesozoic fossil history of asterids.


    Table 13. Mesozoic Stratigraphic Distribution of Asterids.

    Order

    Scientific Name and Publication

    Fossilized Remains

    Malm - Jurassic

    Neocomian - Cretaceous

    Gallic - Cretaceous

    Senonian - Cretaceous

    Assignment in Doubt

    undescribed (Friis et al. 2006)

    flower

    0

    0

    0

    1

    Cornales

    mastixiod fruits (Knobloch and Mai 1986)

    fruits

    0

    0

    0

    >2?

    Ericales

    Actinocalyx bohrii (Friis 1985)

    flowers, fruits, seeds

    0

    0

    0

    1

    Cornales

    Eoepigynia burmensis (Poinar et al. 2007)

    flower

    0

    0

    1

    0

    Ericales

    Eurya (Knobloch and Mai 1986)

    fruits and seeds

    0

    0

    0

    1?

    Cornales

    Hironoia fusiformis (Takahashi et al. 2003)

    flowers

    0

    0

    0

    1

    Ericales

    Leucothoe (Knobloch and Mai 1986)

    fruits and seeds

    0

    0

    0

    1?

    Ericales

    Paleoenkianthus sayrevillensis (Nixon and Crepet 1993)

    flowers and fruits

    0

    0

    1

    0

    Ericales

    Paradinandra suecica (Schönenberger and Friis 2001)

    flowers

    0

    0

    0

    1

    Ericales

    Parasaurauia allonensis (Keller et al. 1996)

    flowers and fruits

    0

    0

    1

    0

    Ericales

    Pentapetalum trifasciculandricus (Martínez-Míllan et al. 2009)

    flowers

    0

    0

    1

    0

    Ericales

    Saurauia (Knobloch and Mai 1986)

    fruits and seeds

    0

    0

    0

    1?

    Assignment in Doubt

    Scandianthus costatus (Friis and Skarby 1982)

    flowers and fruits

    0

    0

    0

    1


    There are two papers dealing with recovery of angiosperm and phytophagous insect clades and European and Neotropical forests following the Chicxulub bolide impact and ensuing K-Pg mass extinction (Wappler et al. 2009 and Wing et al. 2009).

    Studies of the decline of tropical floras following the Oligocene-Eocene climatic cooling, "escape and radiation" coevolution (Winkler et al. 2009), phytophagy (Winkler et al. 2010), basal angiosperm phylogeography (Luna-Vega and Magallón 2010), and the spread and shrinking of Arctic floras during the pluvials, serve as gateways to the vast literature on Cenozoic paleoclimatology, paleontology, and coevolving clades of flowering plants and Holometabola.

    The most comprehensive work on Mesozoic and Cenozoic fossil angiosperms to date is T. N. Taylor et al. (Chapter 22, 2009). A review of the fossil history, evolution, and cladogenesis of flowering plants of the Paleogene and Neogene Period is beyond the scope of the present essay.


    Conclusions on the Evolution of Mesozoic Angiosperms:

    There are great gaps in our understanding of the fossil history of flowering plants based on data recorded in Tables 7-13 and a more detailed review by T. N. Taylor et al. (2009). Paleontologic data reveal several general trends but due to insufficient sampling it is too soon to make any definitive statements on the origin, paleobiodiversity, and evolution of angiosperms.

    Paleobotanical data in the preceding tables often consist of a single specimen from one isolated locality (sometimes only a single, tiny charcoalified flower or seed), and therefore, can no way support assertions of a "Big Bang," "explosive," or "first" radiation of angiosperms in early Cretaceous paleoenvironments. Considerably more field work is needed with possible focus on outcrops older in geologic age.

    In view of the discovery of the Barremian (Neocomian) eudicot Leefructus (G. Sun et al. 2011), I predict that magnoliid, monocot and eudicot fossils will eventually be found in Tithonian (Malm) rocks.

    Coevolution between phytophagous insect antagonists and Carboniferous, Permian, and Triassic seed plant hosts at the level of their respective developmental tool kits and CRMs was likely. I completely reject the notion of a Cretaceous origin of flowering plants. My opinion is supported by molecular phylogenetic analysis of nucleic acid data suggesting a late Triassic (Norian) age of the flowering plant crown group (Stephen A. Smith et al. 2010).

    Potential reticulations in paraphyletic lines of gymnosperms existing at the time of the divergence of angiosperms from the MRCA bracketed by molecular clock studies (Magállon 2010) might be associated with ancient swarms of seed plant WGDs modeled by Jiao et al. (2011) occurring prior to the EPE but after the DeCARB.

    Genomic studies of the cultivated grape overwhelmingly support paleohexaploidy (Jaillon et al. 2007), which is equivalent to the "γ triplication" cited by Jiao et al. (2011) that occurred in the common ancestor of eudicots and monocots.

    Further, our knowledge of carpel, floral, and ovular transcriptional regulators in extant angiosperm model organisms does not preclude derivation of evo-devo models that explain curling, inrolling, and fusion in 260- to 300 million year old spermopteroid Phasmatocycas bridwellii leaves to form carpels, ovaries, and pistils.

    Therefore, 160 million years of neotenic evolution to include condensation of hypothetical gigantopteroid protoflowers is the most simple evo-devo process to explain the origin of reproductive organs in Mesozoic crown group angiosperms and extant basal Amborellanae, Austrobaileyanae, Nymphaeanae, and Magnolianae.

    Adaptive radiation within the major clades of eudicots, rosids, and asterids during the Cretaceous Period is evident from paleontological data summarized by Crepet et al. (2004), Friis et al. (2006), D. E. Soltis et al. (2008), and T. N. Taylor et al. (2009).

    Is the albeit sometimes asynchronous diversification and adaptive radiation of the angiosperm crown group and coevolving insect clades attributable to delayed climatic effects of the BaCCE and other global carbon cycle anomalies triggered by bolide impacts, global warming, undersea volcanism, plate tectonics, and/or island arc orogenesis?

    Clues from our redoubled efforts to excavate ("mining the rock record") and to painstakingly study coalified, compressed, permineralized, petrified, and preserved fossil plant material (page 249, E. L. Taylor and T. N. Taylor 2009), to better understand the anatomy, biology, and morphology of coevolving colonies of holometabolous insect antagonists, and to reconstruct whole protoflowers, might help us solve the riddle of angiosperm beginnings within an evolutionary framework.

    Pteridosperm populations represented by the Paleogene fossil Komlopteris cenozoicus and Oligocene remains of Ptilophyllum muelleri probably survived the K-T extinction radiating with angiosperms and modern conifers in the forests of Tasmania (McLoughlin et al. 2008, McLoughlin et al. 2011).

    Botanists should conduct field surveys and search the museum shelves for unidentified herbarium specimens recording a surviving remnant of a Komlopteris population. This endeavor may be equal in importance to redoubling our efforts to mine and describe early Mesozoic and Paleozoic seed plants, as it would be very important to gain knowledge of homeotic transcriptional regulation in a corystosperm seed fern to compare with other extant vascular plant model organisms.

    Are there any extant bennettitaleans and corystosperms "lurking there," e.g. in unexplored Tasmanian shrub thickets and forest reserves?

    Further, insect-seed plant interactions (vertical infection of baculoviruses, horizontal transfer of mobile chromosome parasites, signaling, and thigmo) reinforced by temperature extremes and global hypoxia may have led to diversification at the molecular level in seed plant and holometabolous insect lineages, formation of protoflowers from bisexual cone axes/spur shoots, coevolutionary development of reproductive modules, and moulting novelties in insect larvae leading to evo-devo of the adult insect head, thorax, and abdomen.

    The origin of angiosperms and certain clades of holometabolous insects is potentially a consequence of coevolution of animal and seed plant CRMs and developmental tool kits. Transposable elements are a potentially unstudied yet ostensibly critical ingredient to coevolution of homeodomain proteins including insect Engraled and angiosperm/gymnosperm LFY enzymes. Further, I suggest that phytoecdysones secreted by Permo-Carboniferous and Permo-Triassic shrub lifeboats, which were essentially coevolutionary compartments, potentially affected body size and moulting time in phytophagous Holometabola.

    Molecular coevolution might have occurred in shrub lifeboat- phytophagous insect- compartments indigenous to biomes of the Carboniferous icehouse and later Permian hothouse Earth. Based on paleobotanical evidence published in the literature, the most likely candidate seed plant receptacles for molecular coevolution with certain Holometabola were Paleozoic gigantopteroids and Vojnovskyales.

    I conclude that insect-mediated intergeneric natural hybridization among populations of Paleozoic gigantopteroids and possibly Vojnovskyales, followed by spontaneous paleopolyploidy, might have been a method through which MIKC-type MADS-box gene duplicates were generated, later spreading molecular novelties in populations of the ancestral early Triassic ghost lineages of angiosperms that survived the EPE.

    Mesozoic times should no longer be the only focus of our quest to solve the riddle of flowering plant evolution. A concerted effort by paleobotanists is needed to identify the putative 160 million year old angiosperm ghost lineage by unearthing, studying, and describing more fossil flowers and fruits from older Cretaceous, Jurassic, and Triassic beds, to include basic paleobotanical surveys of earlier Paleozoic sedimentary deposits.

    The Cretaceous Period is better regarded as a late Mesozoic link between earlier paleofloras and faunas of the Jurassic, Triassic, Permian, and Carboniferous periods, and later insect-plant compartments of the Tertiary (Paleogene and Neogene periods) and Quaternary intervals of the Cenozoic Era.

    A Paleozoic origin of angiosperms is possible based on convincing evidence in the literature that points to deep conservation of floral tool kits. Future tool kit phylogenies should be calibrated with fossils.

    Intractable questions in seed plant evolution may be answered through collaborative, interdisciplinary research studies by biochemists, developmental biologists, entomologists, molecular systematists, and paleobotanists. Understanding a seemingly enigmatic origin of angiosperms is no longer a futile exercise.


    Literature Cited on the Evolution of Mesozoic Angiosperms:

    Allouche, N., C. Apel, M.-T. Martin, V. Dumontet, F. Guéritte, and M. Litaudon. 2009. Cytotoxic sesquiterpenoids from Winteraceae of Caledonian rainforest. Phytochemistry 70(4): 546-553.

    Anderberg, A. A., C. Rydin, and M. Källersjö. 2002. Phylogenetic relationships in the order Ericales s.l.: analyses of molecular data from five genes from the plastid and mitochondrial genomes. American Journal of Botany 89(4): 677-687.

    Anderson, C. L., K. Bremer, and E. M. Friis. 2005. Dating phylogenetically basal eudicots using rbcL sequences and multiple fossil reference points. American Journal of Botany 92(10): 1737-1748.

    Antonelli, A. and I. Sanmartin. 2011. Mass extinction, gradual cooling, or rapid radiation? Reconstructing the spatiotemporal evolution of the ancient angiosperm genus Hedyosmum (Chloranthaceae) using empirical and simulated approaches. Systematic Biology 60(5): 596-615.

    Aoki, S., K. Uehara, M. Imafuku, M. Hasebe, and M. Ito. 2004. Phylogeny and divergence of basal angiosperms inferred from APETALA3- and PISTILLATA-like MADS-box genes. Journal of Plant Research 117(3): 229-244.

    APG III. 2009. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. Botanical Journal of the Linnean Society 161(2): 105-121.

    Arber, E. A. N. and J. Parkin. 1907. On the origin of angiosperms. Botanical Journal of the Linnaean Society 38: 28-80.

    Arias, T. and J. H. Williams. 2008. Embryology of Manekia naranjoana (Piperaceae) and the origin of tetrasporic 16-nucleate female gametophytes in Piperales. American Journal of Botany 95(3): 272-285.

    Axsmith, B. J., R. Serbet, M. Krings, T. N. Taylor, E. L. Taylor, and S. H. Mamay. 2003. The enigmatic Paleozoic plants Spermopteris and Phasmatocycas reconsidered. American Journal of Botany 90(11): 1585-1595.

    Axsmith, B. J., T. N. Taylor, N. C. Fraser, and P. E. Olsen. 1997. An occurrence of the Gondwanan plant Fraxinopsis in the Upper Triassic of Eastern North America. Modern Geology 21: 299-308.

    Azuma, Hiroshi, J. G. Garcia-Franco, V. Rico-Gray, and L. B. Thien. 2001. Molecular phylogeny of the Magnoliaceae: the biogeography of tropical and temperate disjunctions. American Journal of Botany 88(12): 2275-2285.

    Bailey, I. W. and A. C. Smith. 1942. Degeneriaceae, a new family of flowering plants from Fiji. Journal of the Arnold Arboretum 23: 356-365.

    Bailey, I. W. and B. G. L. Swamy. 1948. Amborella trichopoda Baill., a new morphological type of vesselless dicotyledon. Journal of the Arnold Arboretum 29: 245-254.

    Bailey, I. W. and B. G. L. Swamy. 1949. The morphology and relationships of Austrobaileya. Journal of the Arnold Arboretum 30: 211-236.

    Bailey, I. W. and B. G. L. Swamy. 1951. The conduplicate carpel of dicotyledons and its initial trends of specialization. American Journal of Botany 38: 373-379.

    von Balthazar, M. and P. K. Endress. 1999. Floral bract function, flowering process, and breeding systems of Sarcandra and Chloranthus (Chloranthaceae). Plant Systematics and Evolution 218(3-4): 161-178.

    von Balthazar, M., K. R. Pedersen, P. R. Crane, and E. M. Friis. 2008. Carpestella lacunata gen. et sp. nov. a new basal angiosperm flower from the early Cretaceous (early to middle Albian) of eastern North America. International Journal of Plant Sciences 169(7): 890-898.

    von Balthazar, M., K. R. Pedersen, and E. M. Friis. 2005. Teixeiraea lusitanica, a new fossil flower from the Early Cretaceous of Portugal with affinities to Ranunculales. Plant Systematics and Evolution 255(1-2): 55-75.

    von Balthazar, M., J. Schönenberger, W. S. Alverson, H. Janka, C. Bayer, and D. A. Baum. 2006. Structure and evolution of the androecium in the Malvatheca clade (Malvaceae s.l.) and implications for Malvaceae and Malvales. Plant Systematics and Evolution 260(2-4): 171-197.

    Barakat, A., K. Wall, J. Leebens-Mack, Y. J. Wang, J. E. Carlson, and C. W. dePamphilis. 2007. Large-scale identification of microRNAs from a basal eudicot (Eschscholzia californica) and conservation in flowering plants. The Plant Journal 51(6): 991-1003.

    Barreda, V. D., L. Balazzesi, M. C. Tellería, L. Katinas, J. V. Crisci, K. Bremer, M. G. Passalia, R. Corsolini, R. Rodríguez-Brizuela, and F. Bechis. 2010. Eocene Patagonia fossils of the daisy family. Science 329(5999): 1621.

    Bartlett, M. E. and C. D. Specht. 2010. Evidence for the involvement of GLOBOSA-like gene duplications and expression divergence in the evolution of floral morphology in the Zingiberales. New Phytologist 187(2): 521-541.

    Basinger, J. F. and D. L. Dilcher. 1984. Ancient bisexual flowers. Science 224: 511-513.

    Baum, D. A. and L. C. Hileman. 2006. A developmental genetic model for the origin of the flower. Pp. 3-27 In: C. Ainsworth (ed.), Volume 20, Annual Plant Reviews, Flowering and Its Manipulation. Sheffield: Blackwell, 304 pp.

    Behnke, H.-D. 1994. Sieve-element plastids: their significance for the evolution and systematics of the order. Pp. 87-118 In: H.-D. Behnke and T. J. Mabry (eds.), Caryophyllales: Evolution and Systematics. New York: Springer Verlag.

    Beilstein, M. A., N. S. Nagalingum, M. D. Clements, S. R. Manchester, and S. Mathews. 2010. Dated molecular phylogenies indicate a Miocene origin for Arabidopsis thaliana. Proceedings of the National Academy of Sciences 107(43): 18724-18728.

    Belcher, C. M. 2010. From fiery beginnings: wildfires facilitated the spread of angiosperms in the Cretaceous. New Phytologist 188(4): 913-915.

    Bell, C. D., D. E. Soltis, and P. S. Soltis. 2005. The age of the angiosperms: a molecular timescale without a clock. Evolution 59(6): 1245-1258.

    Bell, C. D., D. E. Soltis, and P. S. Soltis. 2010. The age and diversification of the angiosperms revisited. American Journal of Botany 97: 1296-1303.

    Bello, M. A., A. Bruneau, F. Forest, and J. A. Hawkins. 2009. Elusive relationships within order Fabales: phylogenetic analysis using matK and rbcL sequence data. Systematic Botany 34(1): 102-114.

    Berendse, F. and M. Scheffer. 2009. The angiosperm radiation revisited, an ecological explanation for Darwin's 'abominable mystery.' Ecology Letters 12(9): 865-872.

    Bergthorsson, A., O. Richardson, G. J. Young, L. R. Goertzen, and J. D. Palmer. 2004. Massive horizontal transfer of mitochondrial genes from diverse land plant donors to the basal angiosperm Amborella. Proceedings of the National Academy of Sciences 101(51): 17747-17752.

    Bernhardt, P., T. Sage, P. Weston, H. Azuma, M. Lam, L. B. Thien, and J. Bruhl. 2003. The pollination of Trimenia moorei (Trimeniaceae): floral volatiles, insect/wind pollen vectors and stigmatic self-incompatibility in a basal angiosperm. Annals of Botany 92: 445-458.

    Bernhardt, P. and L. B. Thien. 1987. Self-isolation and insect pollination in the primitive angiosperms: new evaluations of older hypotheses. Plant Systematics and Evolution 156(3-4): 159-176.

    Bharathan, G., B.-J. Janssen, E. A. Kellogg, and N. R. Sinha. 1999. Phylogenetic relationships and evolution of the KNOTTED class of plant homeodomain proteins. Molecular Biology and Evolution 16(4): 553-563.

    Bond, W. J. and A. C. Scott. 2010. Fire and the spread of flowering plants in the Cretaceous. New Phytologist 188(4): 1137-1150.

    Botermans, M., M. S. M. Sosef, L. W. Chatrou, and T. L. P. Couvreur. 2011. Revision of the African genus Hexalobus (Annonaceae). Systematic Botany 36(1): 33-48.

    Borsch, T., K. W. Hilu, D. Quandt, V. Wilde, C. Neinhuis, and W. Barthlott. 2003. Noncoding plastid trnT-trnF sequences reveal a well resolved phylogeny of basal angiosperms. Journal of Evolutionary Biology 16(4): 558-576.

    Borsch, T., K. W. Hilu, J. H. Wiersema, C. Löhne, W. Barthlott, and V. Wilde. 2007. Phylogeny of Nymphaea (Nymphaeaceae): evidence from substitutions and microstructural changes in the chloroplast trnT-trnF region. International Journal of Plant Sciences 168(5): 639-671.

    Borsch, T., C. Löhne, and J. Wiersema. 2008. Phylogeny and evolutionary patterns in Nymphaeales: integrating genes, genomes, and morphology. Taxon 57(4): 1052-1081.

    Borsch, T. and P. S. Soltis. 2008. Nymphaeales - the first globally diverse clade? Taxon 57(4): 1051.

    Boyce, C. K and J.-E. Lee. 2010. An exceptional role for flowering plant physiology in the expansion of tropical rainforests and biodiversity. Proceedings of the Royal Society of London, Series B, Biological Sciences 277(1699): 3437-3443.

    Bravi, S., M. R. B. Lumaga, and J. E. Mickle. 2010. Sagaria cilentana gen. et sp. nov. - a new angiosperm fructification from the Middle Albian of southern Italy. Cretaceous Research 31(3): 285-290.

    Bremer, B. 2009. A review of molecular phylogenetic studies of Rubiaceae. Annals of the Missouri Botanical Garden 96(1): 4-26.

    Bremer, B., K. Bremer, N. Heidari, P. Erixon, R. G. Olmstead, A. A. Anderberg, M. Källersjö, and E. Barkhordarian. 2002. Phylogenetics of asterids based on 3 coding and 3 non-coding chloroplast DNA markers and the utility of non-coding DNA at higher taxonomic levels. Molecular Phylogenetics and Evolution 24(2): 274-301.

    Bremer, B. and T. Eriksson. 2009. Time tree of Rubiaceae: phylogeny and dating the family, subfamilies, and tribes. International Journal of Plant Sciences 170(6): 766-793.

    Bremer, K. 2002. Gondwanan evolution of the grass alliance of families (Poales). Evolution 56(7): 1374-1387.

    Bremer, K., E. M. Friis, and B. Bremer. 2004. Molecular phylogenetic dating of asterid flowering plants shows early Cretaceous diversification. Systematic Biology 53(3): 496-505.

    Brockington, S. F., R. Alexandre, J. Ramdial, M. J. Moore, S. Crawley, A. Dhingra, K. Hilu, D. E. Soltis, and P. S. Soltis. 2009. Phylogeny of the Caryophyllales sensu lato: revisiting hypotheses on pollination biology and perianth differentiation in the core Caryophyllales. International Journal of Plant Sciences 170(5): 627-643.

    Brockington, S. F., R. H. Walker, B. J. Glover, P. S. Soltis, and D. E. Soltis. 2011. Complex pigment evolution in the Caryophyllales. New Phytologist 190(4): 854-864.

    Burger, W. C. 1981. Heresy revived: the monocot theory of angiosperm origin. Evolutionary Theory 5: 189-225.

    Burleigh, J. G., M. S. Bansal, O. Eulenstein, S. Hartmann, A. Wehe, and T. J. Vision. 2011. Genome-scale phylogenetics inferring the plant tree of life from 18,896 gene trees. Systematic Biology 60(2): 117-125.

    Buzgo, M., A. S. Chanderbali, S. Kim, Z. Zheng, D. G. Oppenheimer, P. S. Soltis, and D. E. Soltis. 2007. Floral developmental morphology of Persea americana (avocado, Lauraceae): the oddities of male organ identity. International Journal of Plant Sciences 168(3): 261-284.

    Buzgo, M., P. S. Soltis, and D. E. Soltis. 2004. Floral developmental morphology of Amborella trichopoda (Amborellaceae). International Journal of Plant Sciences 165(6): 925-947.

    Cai, Z., C. Penaflor, J. V. Kuehl, J. Leebens-Mack, J. E. Carlson, C. W. dePamphilis, J. L. Boore, and R. K. Jansen. 2006. Complete plastid genome sequences of Drimys, Liriodendron, and Piper: implications for the phylogenetic relationships of magnoliids. BMC Evolutionary Biology 6: 77.

    Calvillo-Canadell, L. and S. R. S. Cevallo-Ferriz. 2007. Reproductive structures of Rhamnaceae from the Cerro del Pueblo (Late Cretaceous, Coahuila) and Coatzingo (Oligocene, Puebla) formations, Mexico. American Journal of Botany 94(10): 1658-1669.

    Canright, J. E. 1952. The comparative morphology and relationships of the Magnoliaceae. I. Trends of specialization in the stamens. American Journal of Botany 39: 484-497.

    Cantrill, D. J., L. Wanntorp, and A. N. Drinnan. 2011. Mesofossil flora from the late Cretaceous of New Zealand. Cretaceous Research 32(2): 164-173.

    Carlquist, S. 1987. Presence of vessels in wood of Sarcandra (Chloranthaceae): comments on vessel origins in angiosperms. American Journal of Botany 74(12): 1765-1777.

    Carlquist, S. 1996. 4. Wood anatomy of primitive angiosperms: new perspectives and syntheses. Pp. 68-90 In: David Winship Taylor and L. J. Hickey (eds.), Flowering Plant Origin, Evolution, and Phylogeny. New York: Chapman and Hall, 403 pp.

    Carlquist, S. 2009. Xylem heterochrony: an unappreciated key to angiosperm origin and diversifications. Botanical Journal of the Linnaean Society 161(1): 26-65.

    Carlquist, S. and E. L. Schneider. 2002. Vessels of Illicium (Illiciaceae): range of pit membrane remnant presence in perforations and other vessel details. International Journal of Plant Sciences 163(5): 755-763.

    Carlquist, S. and E. L. Schneider. 2009. Do tracheid microstructure and the presence of minute crystals link Nymphaeaceae, Cabombaceae, and Hydatellaceae? Botanical Journal of the Linnaean Society 159(4): 572-582.

    Carlquist, S., E. L. Schneider, and C. B. Hellquist. 2009. Xylem of early angiosperms: Nuphar (Nymphaeaceae) has novel tracheid microstructure. American Journal of Botany 96(1): 207-215.

    Carpenter, K. J. 2005. Stomatal architecture and evolution in basal angiosperms. American Journal of Botany 92(10): 1595-1615.

    Carpenter, K. J. 2006. Specialized structures in the leaf epidermis of basal angiosperms: morphology, distribution, and homology. American Journal of Botany 93(5): 665-681.

    Cevallos-Ferriz, S. R. S., E. Estrada-Ruiz, and B. R. Pérez-Hernández. 2008. Phytolaccaceae infructescence from Cerro del Pueblo Formation, Upper Cretaceous (late Campanian), Coahuila, Mexico. American Journal of Botany 95(1): 77-83.

    Chambers, K. L., G. Poinar, Jr., and R. Buckley. 2010. Tropidogyne, a new genus of early Cretaceous eudicots (Angiospermae) from Burmese amber. Novon 20: 23-29.

    Chanderbali, A. S., V. A. Albert, V. E. T. M. Ashworth, M. T. Clegg, R. E. Litz, D. E. Soltis, and P. S. Soltis. 2008. Persea americana (avocado): bringing ancient flowers to fruit in the genomics era. BioEssays 30(4): 386-396.

    Chanderbali, A. S., V. A. Albert, J. Leebens-Mack, N. S. Altman, D. E. Soltis, and P. S. Soltis. 2009. Transcriptional signatures of ancient floral developmental genetics in avocado (Persea americana; Lauraceae). Proceedings of the National Academy of Sciences 106(22): 8929-8934.

    Chanderbali, A. S., S. Kim, M. Buzgo, Z. Zheng, D. G. Oppenheimer, D. E. Soltis, and P. S. Soltis. 2006. Genetic footprints of stamen ancestors guide perianth evolution in Persea (Lauraceae). International Journal of Plant Sciences 167(6): 1075-1089.

    Chase, M. W. 2004. Monocot relationships: an overview. American Journal of Botany 91(10): 1645-1655.

    Chase, M. W., M. F. Fay, D. S. Devey, O. Maurin, N. Rønsted, J. Davies, Y. Pillon, G. Petersen, O. Seberg, M. N. Tamura, C. B. Asmussen, K. Hilu, T. Borsch, J. I. Davis, D. Wm. Stevenson, J. C. Pires, T. J. Givnish, K. J. Sytsma, S. W. Graham, M. A. McPherson, and H. S. Rai. 2006. Multi-gene analyses of monocot relationships: a summary. Pp. 63-75 In: J. T. Columbus, E. A. Friar, C. W. Hamilton, J. M. Porter, L. M. Prince, and M. G. Simpson (eds.), Monocots: Comparative Biology and Evolution, Volume 1, Excluding Poales. Pomona: Rancho Santa Ana Botanic Garden.

    Chase, M. W. and J. L. Reveal. 2009. A phylogenetic classification of land plants to accompany APG III. Botanical Journal of the Linnean Society 161(2): 122-127.

    Chaw, S.-M., C. C. Chang, H. L. Chen, and W. H. Li. 2004. Dating the monocot-dicot divergence and the origin of core eudicots using whole chloroplast genomes. Journal of Molecular Evolution 58(4): 424-441.

    Chen, L., Y. Ren, P. A. Endress, X. H. Tian, and X. H. Zhang. 2007. Floral organogenesis in Tetracentron sinense (Trochodendraceae) and its systematic significance. Plant Systematics and Evolution 264: 183-193.

    Chen, M.-K., I.-C. Lin, and C.-H. Yang. 2008. Functional analysis of three lily (Lilium longiflorum) APETALA1-like MADS-box genes in regulating floral transition and formation. Plant and Cell Physiology 49(5): 704-717.

    Chen, Z.-D., S. R. Manchester, and H.-Y. Sun. 1999. Phylogeny and evolution of the Betulaceae as inferred from DNA sequences, morphology, and paleobotany. American Journal of Botany 86(8): 1168-1181.

    Chitaley, S. D. 1956. On the fructification Tricoccites trigonum Rode from the Deccan Intertrappean series of India. The Palaeobotanist 5: 56-63.

    Chitaley, S. D. and U. R. Kate. 1974. On a new petrified flower Deccananthus savrii gen. et sp. nov. from the Deccan Intertrappean beds of India. The Palaeobotanist 21: 317-320.

    Chitaley, S. D. and M. Z. Patel. 1975. Raoanthus intertrappea, a new petrified flower from India. Palaeontographica B 153: 141-149.

    Christenhusz, M. J. M., J. L. Reveal, A. Farjon, M. F. Gardner, R. R. Mill, and Mark W. Chase. 2011. A new classification and linear sequence of extant gymnosperms. Phytotaxa 19: 55-70.

    Chung, K.-F., H. van der Werff, and C.-I. Peng. 2010. Observations on the floral morphology of Sassafras randaiense (Lauraceae). Annals of the Missouri Botanical Garden 97(1): 1-10.

    Cibrián-Jaramillo and R. A. Martienssen. 2009. Darwin's "abominable mystery": the role of RNA interference in the evolution of flowering plants. Cold Spring Harbor Symposia on Quantitative Biology 74: 267-273.

    del C. Jiménez-Pérez, N. and F. G. Lorea-Hernández. 2009. Identity and delimitation of the American species of Litsea Lam. (Lauraceae): a morphological approach. Plant Systematics and Evolution 283(1-2): 19-32.

    Clement, J. S., T. J. Mabry, H. Wyler, and A. S. Dreiding. 1994. Chemical review and evolutionary significance of betalains. Pp. 247-257 In: H.-D. Behnke and T. J. Mabry (eds.), Caryophyllales: Evolution and Systematics. New York: Springer Verlag.

    Coe, F. G. and A. J. Bornstein. 2009. A new species of Piper (Piperaceae) from Cordillera Nombre de Dios, Honduras. Systematic Botany 34(3): 492-495.

    Coiffard, C., B. Gomez, M. Thiébaut, J. Kvaček, F. Thévenard, D. Néraudeau. 2009. Intramarginal veined Lauraceae leaves from the Albian-Cenomanian of Charente-Maritime (western France). Palaeontology 52(2): 323-336.

    Cornet, B. 1986. The leaf venation and reproductive structures of a late Triassic angiosperm, Sanmiguelia lewisii. Evolutionary Theory 7: 231-309.

    Cornet, B. 1989. The reproductive morphology and biology of Sanmiguelia lewisii, and its bearing on angiosperm evolution in the late Triassic. Evolutionary Trends in Plants 3(1): 25-51.

    Cornet, B. 1993. Dicot-like leaf and flowers from the Late Triassic tropical Newark Supergroup Rift Zone, U.S.A. Modern Geology 19: 81-99.

    Couvreur, T. L. P., M. Botermans, B. J. van Heuven, R. W. J. M. van der Ham. 2008. Pollen morphology within the Monodora clade, a diverse group of five African Annonaceae genera. Grana 47(3): 185-210.

    Couvreur, T. L. P., J. E. Richardson, M. S. M. Sosef, R. H. J. Erkens, and L. W. Chatrou. 2008. Evolution of syncarpy and other morphological characters in African Annonaceae: a posterior mapping approach. Molecular Phylogenetics and Evolution 47(1): 302-318.

    Cracraft, J. 2005. Phylogeny and evo-devo: characters, homology, and the historical analysis of the evolution of development. Zoology 108(4): 345-356.

    Crane, P. R. 1989. Paleobotanical evidence on the early radiation of nonmagnoliid dicotyledons. Plant Systematics and Evolution 162: 165-191.

    Crane, P. R. and D. L. Dilcher. 1984. Lesqueria: an early angiosperm fruiting axis from the mid-Cretaceous. Annals of the Missouri Botanical Garden 71(2): 384-402.

    Crane, P. R., E. M. Friis, and K. R. Pedersen. 1986. Angiosperm flowers from the Lower Cretaceous: fossil evidence on the early radiation of the dicotyledons. Science 232: 852-854.

    Crane, P. R., E. M. Friis, and K. R. Pedersen. 1989. Reproductive structure and function in Cretaceous Chloranthaceae. Plant Systematics and Evolution 165: 211-226.

    Crane, P. R., E. M. Friis, and K. R. Pedersen. 1994. Palaeobotanical evidence on the early radiation of magnoliid angiosperms. Plant Systematics and Evolution (Supplement) 8: 51-71.

    Crane, P. R., E. M. Friis, and K. R. Pedersen. 1995. The origin and early diversification of angiosperms. Nature 374: 27-33.

    Crane, P. R. and P. S. Herendeen. 1996. Cretaceous floras containing angiosperm flowers and fruits from eastern North America. Review of Palaeobotany and Palynology 90: 319-337.

    Crane, P. R., K. R. Pedersen, E. M. Friis, and A. N. Drinnan. 1993. Early Cretaceous (early to middle Albian) platanoid inflorescences associated with Sapindopsis leaves from the Potomac Group of eastern North America. Systematic Botany 18(2): 328-344.

    Crepet, W. L. 1996. Timing in the evolution of derived floral characters: Upper Cretaceous (Turonian) taxa with tricolpate and tricolpate-derived pollen. Review of Palaeobotany and Palynology 90: 339-360.

    Crepet, W. L. and K. J. Niklas. 2009. Darwin's second "abominable mystery": Why are there so many angiosperm species? American Journal of Botany 96(1): 366-381.

    Crepet, W. L. and K. C. Nixon. 1996. 2. The fossil history of stamens. Pp. 25-57 In: W. D. D'Arcy and R. C. Keating, eds., The Anther: Form, Function, and Phylogeny. New York: Cambridge University Press, 351 pp.

    Crepet, W. L. and K. C. Nixon. 1998. Two new fossil flowers of magnoliid affinity from the Late Cretaceous of New Jersey. American Journal of Botany 85: 1273-1288.

    Crepet, W. L., K. C. Nixon, E. M. Friis, and J. V. Freudenstein. 1992. Oldest fossil flowers of hamamelidaceous affinity from the Late Cretaceous of New Jersey. Proceedings of the National Academy of Sciences 89(19): 8986-8989.

    Crepet, W. L., K. C. Nixon, and M. A. Gandolfo. 2004. Fossil evidence and phylogeny: the age of major angiosperm clades based on mesofossil and macrofossil evidence from Cretaceous deposits. American Journal of Botany 91(10): 1666-1682.

    Crepet, W. L., K. C. Nixon, and M. A. Gandolfo. 2005. An extinct calycanthoid taxon Jerseyanthus calycanthoides from Late Cretaceous of New Jersey. American Journal of Botany 92(9): 1475-1485.

    Cronquist, A. 1981. An Integrated System of Flowering Plants. New York: Columbia University Press, 1,262 pp.

    Cuenca, A., G. Petersen, O. Seberg, J. I. Davis, and D. W. Stevenson. 2010. Are substitution rates and RNA editing correlated? BMC Evolutionary Biology 10: 349.

    Cuénoud, V. Savolainen, L. W. Chatrou, M. Powell, R. J. Grayer, and M. W. Chase. 2002. Molecular phylogenetics of Caryophyllales based on nuclear 18S rDNA and plastid rbcL, atpB, and matK DNA sequences. American Journal of Botany 89(1): 132-144.

    Daghlian, C. P. 1981. A review of the fossil record of monocotyledons. Botanical Review (Lancaster) 47(4): 517-554.

    Dahlgren, R. M. T. 1980. A revised system of classification of the angiosperms. Botanical Journal of the Linnean Society 80: 91-124.

    Dahlgren, R. M. T. and H. T. Clifford. 1982. The Monocotyledons: A Comparative Study. New York: Academic Press, 378 pp.

    Dahlgren, R. M. T., H. T. Clifford, and P. F. Yeo. 1985. The Families of Monocotyledons. New York: Springer Verlag, 520 pp.

    Davies, T. J., T, G. Barraclough, M. W. Chase, P. S. Soltis, D. E. Soltis, and V. Savolainen. 2004. Darwin's abominable mystery: insights from a supertree of the angiosperms. Proceedings of the National Academy of Sciences 101: 1904-1909.

    Davis, C. C., C. O. Webb, K. J. Wurdack, C. A. Jaramillo, and M. J. Donoghue. 2005. Explosive radiation of Malpighiales supports a mid-Cretaceous origin of modern tropical rain forests. The American Naturalist 165(3): E36-E65.

    De Bodt, S., G. Theissen, and Y. Van de Peer. 2006. Promoter analysis of MADS-box genes in eudicots through phylogenetic footprinting. Molecular Biology and Evolution 23(6): 1293-1303.

    Delevoryas, T. and J. E. Mickle. 1995. Upper Cretaceous magnoliaceous fruit from British Columbia. American Journal of Botany 82(7): 763-768.

    Denk, T. and I.-C. Oh. 2005. Phylogeny of Schisandraceae based on morphological data: evidence from modern plants and the fossil record. Plant Systematics and Evolution 256(1-4): 113-145.

    Dettmann, M. E., H. T. Clifford, and M. Peters. 2009. Lovellea wintonensis gen. et sp. nov. – early Cretaceous (late Albian), anatomically preserved, angiospermous flowers and fruits from the Winton Formation, western Queensland, Australia. Cretaceous Research 30(2): 339-355.

    Dettmann, M. E. and D. M. Jarzen. 1998. The early history of Proteaceae in Australia: the pollen record. Australian Systematic Botany 11: 401-438.

    Dilcher, D. L. 1979. Early angiosperm reproduction: an introductory report. Review of Palaeobotany and Palynology 27: 291-328.

    Dilcher, D. L. 2010. Major innovations in angiosperm evolution. Pp. 97-116 In: C. T. Gee (ed.), Plants in Mesozoic Time, Morphological Innovations, Phylogeny, Ecosystems. Bloomington: Indiana University Press, 373 pp.

    Dilcher, D. L. and P. W. Basson. 1990. Mid-cretaceous angiosperm leaves from a new fossil locality in Lebanon. Botanical Gazette 151(4): 538-547.

    Dilcher, D. L. and P. R. Crane. 1985. Archaeanthus: An early angiosperm from the Cenomanian of the western interior of North America. Annals of the Missouri Botanical Garden 71(2): 351-383.

    Dilcher, D. L. and W. L. Kovach. 1986. Early angiosperm reproduction: Caloda delevoryana gen. et sp. nov., a new fructification from the Dakota Formation (Cenomanian) of Kansas. American Journal of Botany 73(8): 1230-1237.

    Dilcher, D., G. Sun, Q. Ji, and H. Li. 2007. An early infructescence Hyrcantha decussata (comb. nov.) from the Yixian Formation in northeastern China. Proceedings of the National Academy of Sciences 104(22): 9370-9374.

    Dilcher, D. L. and H. Wang. 2009. An early Cretaceous fruit with affinities to Ceratophyllaceae. American Journal of Botany 96(12): 2256-2269.

    Donoghue, M. J. and J. A. Doyle. 1989. Phylogenetic analysis of angiosperms and the relationships of Hamamelidae. Pp. 17-45 In: P. R. Crane and S. Blackmore (eds.), Evolution, Systematics, and Fossil History of the Hamamelidae, Volume 1. New York: Oxford University Press, 305 pp.

    Donoghue, M. J., R. H. Ree, and D. A. Baum. 1998. Phylogeny and the evolution of flower symmetry in the Asteridae. Trends in Plant Science 3: 311-317.

    Dorn, A. S., D. H. Les, M. L. Moody, and W. E. Phillips. 2004. Nymphaea "William Phillips," a new intersubgeneric hybrid. HortScience 39(2): 446-447.

    Doust, A. N. 2001. The developmental basis of floral variation in Drimys winteri (Winteraceae). International Journal of Plant Sciences 162(4): 697-717.

    Doyle, J. A. 2000. Paleobotany, relationships, and geographic history of Winteraceae. Annals of the Missouri Botanical Garden 87: 303-316.

    Doyle, J. A. 2008. Integrating molecular phylogenetic and paleobotanical evidence on origin of the flower. International Journal of Plant Sciences 169(7): 816-843.

    Doyle, J. A. and M. J. Donoghue. 1993. Phylogenies and angiosperm diversification. Paleobiology 19(2): 141-167.

    Doyle, J. A., H. Eklund, and P. S. Herendeen. 2003. Floral evolution in Chloranthaceae: implications of a morphological phylogenetic analysis. International Journal of Plant Sciences 164(Supplement 5): S365-S382.

    Doyle, J. A. and P. K. Endress. 2000. Morphological phylogenetic analysis of basal angiosperms: comparison and combination with molecular data. International Journal of Plant Sciences 161(Supplement 6): S121-S153.

    Doyle, J. A. and P. K. Endress. 2010. Integrating early Cretaceous fossils into the phylogeny of living angiosperms: Magnoliidae and eudicots. Journal of Systematics and Evolution 48(1): 1-35.

    Doyle, J. A., P. K. Endress, and G. R. Upchurch, Jr. 2008. Early Cretaceous monocots: a phylogenetic evaluation. Acta Musei Nationalis Pragae, Series B, Historia Naturalis 64: 59-87.

    Drinnan, A. N., E. M. Friis, and K. R. Pedersen. 1990. Lauraceous flowers from the Potomac Group (mid-Cretaceous) of eastern North America. Botanical Gazette 151: 370-384.

    Drinnan, A. N., P. R. Crane, E. M. Friis, and K. R. Pedersen. 1991. Angiosperm flowers and tricolpate pollen of buxaceous affinity from the Potomac Group (mid-Cretaceous) of eastern North America. American Journal of Botany 78(2): 153-176.

    Drinnan, A. N., P. R. Crane, and S. B. Hoot. 1994. Patterns of floral evolution in the early diversification of non-magnoliid dicotyledons (eudicots). Plant Systematics and Evolution (Supplement) 8: 93-121.

    Duarte, J. M., K. P. Wall, L. M. Zahn, P. S. Soltis, D. E. Soltis, J. Leebens-Mack, J. E. Carlson, H. W. Ma, and C. W. dePamphilis. 2008. Utility of Amborella trichopoda and Nuphar advena expressed sequence tags for comparative sequence analysis. Taxon 57(4): 1110-1122.

    Ehrlich, P. R. and P. H. Raven. 1964. Butterflies and plants: a study in coevolution. Evolution 18: 586-608.

    Eklund, H. 2000. Lauraceous flowers from the Late Cretaceous of North Carolina, USA. Botanical Journal of the Linnaean Society 132: 397-428.

    Eklund, H. 2003. First Cretaceous flowers from Antarctica. Review of Palaeobotany and Palynology 127: 187-217.

    Eklund, H., J. E. Francis, and D. J. Cantrill. 2004. A Late Cretaceous mesofossil assemblage from Table Nunatak, Antarctica: lycopods, ferns and vegetative structures of conifers and angiosperms. Cretaceous Research 26: 211-228.

    Eklund, H., E. M. Friis, and K. R. Pedersen. 1997. Chloranthaceous floral structures from the Late Cretaceous of Sweden. Plant Systematics and Evolution 207: 13-42.

    Eklund, H. and J. Kvacek. 1998. Lauraceous inflorescences and flowers from the Cenomanian of Bohemia (Czech Republic, central Europe). International Journal of Plant Sciences 159: 668-686.

    El-Soughier, M., R. C. Mehrotra, Z.-Y. Zhou, and G.-L. Shi. 2011. Nypa fruits and seeds from the Maastrichtian-Danian sediments or Bir Abu Minqar, southwestern desert, Egypt. Palaeoworld 20(1): 75-83.

    Endress, P. K. 1980. The reproductive structures and systematic position of the Austrobaileyaceae. Botanische Jahrbücher für Systematik, Pflanzengeshichte und Pflanzengeographie 101: 393-433.

    Endress, P. K. 1983. The early floral development of Austrobaileya. Botanische Jahrbücher für Systematik, Pflanzengeshichte und Pflanzengeographie 103: 481-497.

    Endress, P. K. 1984. The role of inner staminodes in the floral display of some relict Magnoliales. Plant Systematics and Evolution 146: 269-282.

    Endress, P. K. 1994. Diversity and Evolutionary Biology of Tropical Flowers. Cambridge University Press: Cambridge, 511 pp.

    Endress, P. K. 2001. Origins of flower morphology. Chapter 21, Pp. 493-510 In: G. P. Wagner (ed.), The Character Concept in Evolutionary Biology, San Diego: Academic Press, 622 pp.

    Endress, P. K. 2001. The flowers in extant basal angiosperms and inferences on ancestral flowers. International Journal of Plant Sciences 162(5): 1111-1140.

    Endress, P. K. 2003. Morphology and angiosperm systematics in the molecular era. The Botanical Review 68(4): 545-570.

    Endress, P. K. 2004. Structure and relationships of basal relictual angiosperms. Australian Systematic Botany 17(4): 343-366.

    Endress, P. K. 2008. Perianth biology in the basal grade of extant angiosperms. International Journal of Plant Sciences 169(7): 844-862.

    Endress, P. A. 2010. The evolution of floral biology in basal angiosperms. Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences 365(1539): 411-421.

    Endress, P. A. 2010. Synorganization without organ fusion in the flowers of Geranium robertianum (Geraniaceae) and its not so trivial obdiplostemony. Annals of Botany 106(5): 687-695.

    Endress, P. A. 2010. Flower structure and trends of evolution in eudicots and their major subclades. Annals of the Missouri Botanical Garden 97(4): 541-583.

    Endress, P. K. and J. E. Armstrong. 2011. Floral development and floral phyllotaxis in Anaxagorea (Annonaceae). Annals of Botany 108(5): 835-845.

    Endress, P. K. and J. A. Doyle. 2007. Floral phyllotaxis in basal angiosperms: development and evolution. Current Opinion in Plant Biology 10: 52-57.

    Endress, P. K. and J. A. Doyle. 2009. Reconstructing the ancestral angiosperm flower and its initial specializations. American Journal of Botany 96(1): 22-66.

    Endress, P. K. and E. M. Friis. 1991. Archamamelis, hamamelidalean flowers from the upper Cretaceous of Sweden. Plant Systematics and Evolution 175: 101-114.

    Endress, P. K. and E. M. Friis. 2006. Rosids - reproductive structures, fossil and extant, and their bearing on deep relationships: introduction. Plant Systematics and Evolution 260(2-4): 83-85.

    Endress, P. K. and L. D. Hufford. 1989. The diversity of stamen structures and dehiscence patterns among Magnoliidae. Botanical Journal of the Linnaean Society 100: 45-85.

    Endress, P. K. and A. Igersheim. 2000. The reproductive structures of the basal angiosperm Amborella trichopoda (Amborellaceae). International Journal of Plant Sciences 161(Supplement 6): S237-S248.

    Endress, P. K. and M. L. Matthews. 2006. Elaborate petals and staminodes in eudicots: diversity, function, and evolution. Organisms Diversity and Evolution 6(4): 257-293.

    Endress, P. K. and M. L. Matthews. 2006. First steps towards a floral structural characterization of the major rosid subclades. Plant Systematics and Evolution 260(2-4): 223-251.

    Engler, A. 1964. Syllabus der Pflanzenfamilien. Berlin: Gebruder Borntraeger, 666 pp.

    Estrada-Ruiz, E., G. R. Upchurch, Jr., J. A. Wolfe, and S. R. S. Cevallos-Ferriz. 2011. Comparative morphology of fossil and extant leaves of Nelumbonaceae, including a new genus from the late Cretaceous of western North America. Systematic Botany 36(2): 337-351.

    Feild, T. S. and N. C. Arens. 2007. The ecophysiology of early angiosperms. Plant, Cell and Environment 30(3): 291-309.

    Feild, T. S., N. C. Arens, and T. E. Dawson. 2003. The ancestral ecology of angiosperms: emerging perspectives from extant basal lineages. International Journal of Plant Sciences 164(Supplement 3): S129-S142.

    Feild, T. S., T. J. Brodribb, T. Jaffré, and N. M. Holbrook. 2001. Acclimation of leaf anatomy, photosynthetic light use, and xylem hydraulics to light in Amborella trichopoda (Amborellaceae). International Journal of Plant Sciences 162(5): 999-1008.

    Feild, T. S., , P. J. Hudson, L. Balun, D. S. Chatelet, A. A. Patino, C. A. Sharma, and K. McLaren. 2011. The ecophysiology of xylem hydraulic constraints by "basal" vessels in Canella winterana (Canellaceae). International Journal of Plant Sciences 172(7): 879-888.

    Feild, T. S., G. R. Upchurch, Jr., D. S. Chatelet, T. J. Brodribb, K. C. Grubbs, M.-S. Samain, and S. Wanke. 2011. Fossil evidence for low gas exchange capacities for early Cretaceous angiosperm leaves. Paleobiology 37(2): 195-213.

    Feitoza, L. L., L. P. Felix, A. A. J. F. Castro, and R. Carvalho. 2009. Cytogenetics of Alismatales, s.s.: chromosomal evolution and C-banding. Plant Systematics and Evolution 280(1-2): 119-131.

    Feng, C.-M., S. R. Manchester, and Q.-Y. Xiang. 2009. Phylogeny and biogeography of Alangiaceae (Cornales) inferred from DNA sequences, morphology, and fossils. Molecular Phylogenetics and Evolution 51(2): 201-214.

    Feng, C.-M., Q.-Y. Xiang, and R. G. Franks. 2011. Phylogeny-based developmental analyses illuminate evolution of inflorescence architectures in dogwoods (Cornus s.l., Cornaceae) New Phytologist 191(3): 850-869.

    Fishbein, M., C. Hibsch-Jetter, D. E. Soltis, and L. Hufford. 2001. Phylogeny of Saxifragales (angiosperms, eudicots): analysis of a rapid, ancient radiation. Systematic Biology 50(6): 817-847.

    Floyd, S. K. and W. E. Friedman. 2000. Evolution of endosperm developmental patterns among basal flowering plants. International Journal of Plant Sciences 161(Supplement 6): S51-S81.

    Friedman, W. E. 2001. Comparative embryology of basal angiosperms. Current Opinion in Plant Biology 4: 14-20.

    Friedman. W. E. 2008. Hydatellaceae are water lilies with gymnospermous tendencies. Nature 453: 94-97.

    Friedman, W. E., W. N. Gallup, and J. H. Williams. 2003. Female gametophyte development in Kadsura: implications for Schizandraceae, Illiciales, and the early evolution of flowering plants. International Journal of Plant Sciences 164 (Supplement): S293-S305.

    Friedman, W. E. and K. C. Ryerson. 2009. Reconstructing the ancestral female gametophyte of angiosperms: insights from Amborella and other ancient lineages of flowering plants. American Journal of Botany 96(1): 129-143.

    Friis, E. M. 1983. Upper Cretaceous (Senonian) floral structures of juglandalean affinity containing Normapollis pollen. Review of Palaeobotany and Palynology 39: 161-188.

    Friis, E. M. 1985. Actinocalyx gen. nov., sympetalous angiosperm flowers from the upper Cretaceous of southern Sweden. Review of Palaeobotany and Palynology 45: 171-183.

    Friis, E. M. 1988. Spirematospermum chandlerae sp. nov., an extinct species of Zingiberaceae from the North American Cretaceous. Tertiary Research 9: 7-12.

    Friis, E. M. 1990. Silvianthemum suecicum gen. et sp. nov., a new saxifragalean flower from the late Cretaceous of Sweden. Biologiske Skrifter 36: 5-21.

    Friis, E. M. and P. R. Crane. 1989. Reproductive structures of Cretaceous Hamamelidae: Pp. 155-174 In: P. R. Crane and S. Blackmore (eds.), Evolution, Systematics, and Fossil History of the Hamamelidae, Volume 1. New York: Oxford University Press, 305 pp.

    Friis, E. M. and P. R. Crane. 2007. A new home for tiny aquatics. Nature 446: 269-270.

    Friis, E. M., P. R. Crane, and K. R. Pedersen. 1986. Floral evidence for Cretaceous chloranthoid angiosperms. Nature 320: 163-164.

    Friis, E. M., P. R. Crane, and K. R. Pedersen. 1988. The reproductive structures of Cretaceous Platanaceae. Det Kongelige Danske Videnskabernes Selskab Biologiske Skrifter 31: 1-55.

    Friis, E. M., P. R. Crane, and K. R. Pedersen. 1997. Anacostia, a new basal angiosperm from the Early Cretaceous of North America and Portugal with monocolpate/trichotomocolpate pollen. Grana 36: 225-244.

    Friis, E. M., P. R. Crane, and K. R. Pedersen. 1997. Fossil history of magnoliid angiosperms. Pp. 121-156 In: K. Iwatsuki and P. H. Raven (eds.), Evolution and Diversification of Land Plants. Tokyo: Springer-Verlag, 330 pp.

    Friis, E. M., J. A. Doyle, P. K. Endress, and Q. Leng. 2003. Archaefructus- angiosperm precursor or specialized early angiosperm? Trends in Plant Science 8: 369-373.

    Friis, E. M., H. Eklund, K. R. Pedersen, and P. R. Crane. 1994. Virginianthus calycanthoides gen. et sp. nov. - a calycanthaceous flower from the Potomac Group (early Cretaceous) of eastern North America. International Journal of Plant Sciences 155(6): 772.

    Friis, E. M. and K. R. Pedersen. 2011. Canrightia resinifera gen. et sp. nov., a new extinct angiosperm with Retimonocolpites-type pollen from the early Cretaceous of Portugal: missing link in the eumagnoliid tree? Grana 50(1): 3-29.

    Friis, E. M., K. R. Pedersen, M. von Balthazar, G. W. Grimm, and P. R. Crane. 2009. Monetianthus mirus gen. et sp. nov., a Nymphaealean flower from the early Cretaceous of Portugal. International Journal of Plant Sciences 170(8): 1086-1101.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 1992. Esquieria gen. nov., fossil flowers with combretaceous features from the late Cretaceous of Portugal. Biologiske Skrifter 41: 1-45.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 1995. Appomattoxia ancistrophora gen. et sp. nov., a new early Cretaceous plant with similarities to Circaeaster and extant Magnoliidae. American Journal of Botany 82(7): 933-943.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2000. Fossil floral structures of a basal angiosperm with monocolpate, reticulate-acolumellate pollen from the early Cretaceous of Portugal. Grana 39: 226-245.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2000. Reproductive structure and organization of basal angiosperms from the early Cretaceous (Barremian or Aptian) of western Portugal. International Journal of Plant Sciences 161(Supplement 6): S169-S182.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2001. Fossil evidence of water lilies (Nymphaeales) in the early Cretaceous. Nature 410: 357-360.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2004. Araceae from the early Cretaceous of Portugal: evidence on the emergence of monocotyledons. Proceedings of the National Academy of Sciences 101(47): 16565-16570.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2005. When Earth started blooming: insights from the fossil record. Current Opinion in Plant Biology 8(1): 5-12.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2006. Cretaceous angiosperm flowers: innovation and evolution in plant reproduction. Palaeogeography, Palaeoclimatology, and Palaeoecology 232: 251-293.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2009. Early Cretaceous mesofossils from Portugal and eastern North America related to the Bennettitales-Erdtmanithecales-Gnetales group. American Journal of Botany 96(1): 252-283.

    Friis, E. M., K. R. Pedersen, and P. R. Crane. 2010. Diversity in obscurity: fossil flowers and the early history of angiosperms. Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences 365(1539): 369-382.

    Friis, E. M., K. R. Pedersen, and J. Schönenberger. 2003. Endressianthus, a new Normapolles producing plant genus of fagalean affinity from the late Cretaceous of Portugal. International Journal of Plant Sciences 164 (Supplement 5): S201-S223.

    Friis, E. M., K. R. Pedersen, and J. Schönenberger. 2006. Normapolles plants: a prominent component of the Cretaceous rosid diversification. Plant Systematics and Evolution 260(2-4): 107-140.

    Friis, E. M. and A. Skarby. 1981. Structurally preserved angiosperm flowers from the Upper Cretaceous of southern Sweden. Nature 291: 484-486.

    Friis, E. M. and A. Skarby. 1982. Scandianthus gen. nov., angiosperm flowers of Saxifragalean affinity from the Upper Cretaceous of southern Sweden. Annals of Botany 50: 569-583.

    Frohlich, M. W. and M. W. Chase. 2007. After a dozen years of progress the origin of angiosperms is still a great mystery. Nature 450: 1184-1189.

    Frumin, S. and E. M. Friis. 1996. Liriodendroid seeds from the Late Cretaceous of Kazakhstan and North Carolina, USA. Review of Palaeobotany and Palynology 94: 39-55.

    Frumin, S. and E. M. Friis. 1999. Magnoliid reproductive organs from the Cenomanian-Turonian of north-western Kazakhstan: Magnoliaceae and Illiciaceae. Plant Systematics and Evolution 216: 265-288.

    Frumin, S., H. Eklund, and E. M. Friis. 2004. Mauldinia hirsuta sp. nov., a new member of the extinct genus Mauldinia (Lauraceae) from the Late Cretaceous (Cenomanian-Turonian) of Kazakhstan. International Journal of Plant Sciences 165(5): 883-895.

    Furness, C. A. and H. Banks. 2010. Pollen evolution in the early divergent monocot order Alismatales. International Journal of Plant Sciences 171(7): 713-739.

    Furness, C. A. and P. J. Rudall. 2001. The tapetum in basal angiosperms: early diversity. International Journal of Plant Sciences 162(2): 375-392.

    Gamerro, J. C. and V. Barreda. 2008. New fossil record of Lactoridaceae in southern South America: a palaeobiogeographical approach. Botanical Journal of the Linnaean Society 158(1): 41-50.

    Gandolfo, M. A. and R. N. Cuneo. 2005. Fossil Nelumbonaceae from the La Colonia Formation (Campanian-Maastrichtian, Upper Cretaceous), Chubut, Patagonia, Argentina. Review of Palaeobotany and Palynology 133(3-4): 169-178.

    Gandolfo, M. A., K. C. Nixon, and W. L. Crepet. 1998. A new fossil flower from the Turonian of New Jersey: Dressiantha bicarpellata gen. et sp. nov. (Capparales). American Journal of Botany 85(7): 964-974.

    Gandolfo, M. A., K. C. Nixon, and W. L. Crepet. 1998. Tylerianthus crossmanensis gen. et sp. nov. (Aff. Hydrangeaceae) from the upper Cretaceous of New Jersey. American Journal of Botany 85(3): 376-386.

    Gandolfo, M. A., K. C. Nixon, and W. L. Crepet. 2002. Triuridaceae fossil flowers from the Upper Cretaceous of New Jersey. American Journal of Botany 89(12): 1940-1957.

    Gandolfo, M. A., K. C. Nixon, and W. L. Crepet. 2004. Cretaceous flowers of Nymphaeaceae and implications for complex insect entrapment pollination mechanisms in early angiosperms. Proceedings of the National Academy of Sciences 101(21): 8056-8060.

    García-González, R., B. Carrasco, P. Peñaillo, L. Letelier, R. Herrera, B. Lavandero, M. Moya, and P. S. Caligari. 2008. Genetic variability and structure of Gomortega keule (Molina) Baillon (Gomortegaceae) relict populations: geographical and genetic fragmentation and its implications for conservation. Canadian Journal of Botany 86(11): 1299-1310.

    García-Robledo, C. and C. L. Staines. 2008. Herbivory in gingers from latest Cretaceous to present: is the ichnogenus Cephaloleichnites (Hispinae, Coleoptera) a rolled-leaf beetle? Journal of Paleontology 82(5): 1035-1037.

    Givnish, T. J., M. Ames, J. R. McNeal, M. R. McKain, P. R. Steele, C. W. dePamphilis, Sean W. Graham, J. C. Pires, D. Wm. Stevenson, W. B. Zomlefer, B. G. Briggs, M. R. Duvall, M. J. Moore, J. M. Heaney, D. E. Soltis, P. S. Soltis, K. Thiele, and J. H. Leebens-Mack. 2011. Assembling the tree of monocotyledons: plastome sequence phylogeny and evolution of Poales. Annals of the Missouri Botanical Garden 97(4): 584-616.

    Givnish, T. J., K. C. Millam, T. M. Evans, J. C. Hall, J. C. Pires, P. E. Berry, and K. J. Sytsma. 2004. Ancient vicariance or recent long distance dispersal? Inferences about phylogeny and South American-African disjunctions in Rapateaceae and Bromeliaceae based on ndhF sequence data. International Journal of Plant Sciences 165(Supplement 4): S35-S54.

    Golovneva, L. B. 2008. A new platanaceous genus Tasymia (angiosperms) from the Turonian of Siberia. Paleontologicheskii Zhurnal 42(2): 192.

    Golovneva, L. B. 2010. The taxonomy and morphological diversity of leaves of Paraprotophyllum (Platanaceae) from the late Cretaceous of Sakhalin Island. Paleontologicheskii Zhurnal 44(10): 1270-1280.

    Gomez, B., C. Coiffard, L. M. Sender, C. Martín-Closas, U. Villanueva-Amadoz, and J. Ferrer. 2009. Klitzschphyllites, aquatic basal eudicots (Ranunculales?) from the Upper Albian (Lower Cretaceous) of northeastern Spain. International Journal of Plant Sciences 170(8): 1075-1085.

    Goodrich, K. R. and R. A. Raguso. 2009. The olfactory component of floral display in Asimina and Deeringothamnus (Annonaceae). New Phytologist 183: 457-469.

    Gorelick, R. 2001. Did insect pollination cause increased seed plant diversity? Biological Journal of the Linnaean Society 74: 407-427.

    Goremykin, V. V., K. I. Hirsch-Ernst, S. Wölfl, and F. H. Hellwig. 2003. Analysis of the Amborella trichopoda chloroplast genome sequence suggests that Amborella is not a basal angiosperm. Molecular Biology and Evolution 20(9): 1499-1505.

    Graur, D. and W. Martin. 2004. Reading the entrails of chickens: molecular timescales of evolution and the illusion of precision. Trends in Genetics 20(2): 80-86.

    Graham, A. 2009. Fossil record of the Rubiaceae. Annals of the Missouri Botanical Garden 96(1): 90-108.

    Graham, S. W. and R. G. Olmstead. 2000. Utility of 17 chloroplast genes for inferring the phylogeny of basal angiosperms. American Journal of Botany 87(11): 1712-1730.

    Grob, V., P. Moline, E. Pfeifer, A. R. Novelo, and R. Rutishauser. 2006. Developmental morphology of branching flowers in Nymphaea prolifera. Journal of Plant Research 119(6): 561-570.

    Hall, J. C., H. H. Iltis, and K. J. Sytsma. 2004. Molecular phylogenetics of core Brassicales, placement of orphan genera Emblingia, Forchammeria, Tirania, and character evolution. Systematic Botany 29: 654-669.

    Hao, G., R. M. K. Saunders, and M.-L. Chye. 2000. A phylogenetic analysis of the Illiciaceae based on sequences of internal transcribed spacers (ITS) of nuclear ribosomal DNA. Plant Systematics and Evolution 223(1-2): 81-90.

    Heimhofer, U., P. A. Hochuli, S. Burfa, J. M. L. Dinis, and H. Weissert. 2005. Timing of Early Cretaceous angiosperm diversification and possible links to major paleoenvironmental change. Geology 33(2): 141-144.

    Herendeen, P. S., P. R. Crane, and A. N. Drinnan. 1995. Fagaceous flowers, fruits, and cupules from the Campanian (Late Cretaceous) of central Georgia, USA. International Journal of Plant Sciences 156(1): 93-116.

    Herendeen, P. S., S. Magallon-Puebla, S. Lupia, P. R. Crane, and J. Kobaylinska. 1999. A preliminary conspectus of the Allon flora from the Late Cretaceous (Late Santonian) of central Georgia, USA. Annals of the Missouri Botanical Garden 86: 407-471.

    Herendeen, P. S., K. C. Nixon, and W. L. Crepet. 1994. Fossil flowers and pollen of Lauraceae from the Upper Cretaceous of New Jersey. Plant Systematics and Evolution 189: 29-40.

    Hermsen, E. J., M. A. Gandolfo, K. C. Nixon, and W. L. Crepet. 2003. Divisestylus gen. nov. (aff. Iteaceae), a fossil saxifrage from the late Cretaceous of New Jersey, USA. American Journal of Botany 90(9): 1373-1388.

    Hermsen, E. J., K. C. Nixon, and W. L. Crepet. 2006. The impact of extinct taxa on understanding the early evolution of angiosperm clades: an example incorporating fossil reproductive structures of Saxifragales. Plant Systematics and Evolution 260(2-4): 141-169.

    Hernandez-Castillo, G. R. and S. R. S. Cevallos-Ferriz. 1999. Reproductive and vegetative organs with affinities to Halogoraceae from the Upper Cretaceous Huepac Chert locality of Sonora, Mexico. American Journal of Botany 86(10): 1717-1734.

    Herngreen, G. F. W., M. Kedves, L. V. Rovnina, and S. B. Smirnova. 1996. Cretaceous palynofloral provinces: a review. Pp. 1157-1188 In: J. Jansonius and D. C. McGregor (eds.), Palynology: Principles and Applications. Salt Lake City: American Association of Stratigraphic Palynologists Foundation.

    Hesse, M. 2001. Pollen characters of Amborella trichopoda (Amborellaceae): a reinvestigation. International Journal of Plant Sciences 162(1): 201-208.

    Hickey, L. J. and J. A. Doyle. 1977. Early Cretaceous fossil evidence for angiosperm evolution. Botanical Review (Lancaster) 43: 3-104.

    Hileman, L. C. and V. F. Irish. 2009. More is better: the uses of developmental genetic data to reconstruct perianth evolution. American Journal of Botany 96(1): 83-95.

    Hilu, K. W., C. Black, D. Diouf, and J. G. Burleigh. 2008. Phylogenetic signal in matK vs. trnK: a case study in early diverging eudicots (angiosperms). Molecular Phylogenetics and Evolution 48(3): 1120-1130.

    Hilu, K. W., T. Borsch, K. Müller, D. E. Soltis, P. S. Soltis, V. Savolainen, M. W. Chase, M. P. Powell, L. A. Alice, R. Evans, H. Sauquet, C. Neinhuis, T. A. B. Slotta, J. G. Rohwer, C. S. Campbell, and L. W. Chatrou. 2003. Angiosperm phylogeny based on <011>matK sequence information. American Journal of Botany 90(12): 1758-1776.

    Hisamoto, Y., H. Kashiwagi, and M. Kobayashi. 2008. Use of flowering gene FLOWERING LOCUS T (FT) homologs in the phylogenetic analysis of bambusoid and early diverging grasses. Journal of Plant Research 121(5): 451-461.

    Hochuli, P. A. and S. Feist-Burkhardt. 2004. A boreal early cradle of angiosperms? Angiosperm-like pollen from the Middle Triassic of the Barents Sea (Norway). Journal of Micropalaeontology 23: 97-104.

    Holloway, S. J. and W. E. Friedman. 2008. Embryological features of Tofieldia glutinosa and their bearing on the early diversification of monocotyledonous plants. Annals of Botany 102(2): 167-182.

    Hoot, S. B., S. Magallón, and P. R. Crane. 1999. Phylogeny of basal eudicots based on three molecular data sets: atpB, rbcL, and 18S nuclear ribosomal DNA sequences. Annals of the Missouri Botanical Garden 86(1): 1-32.

    Horner, H. T., S. Wanke, and M.-S. Samain. 2009. Evolution and systematic value of leaf crystal macropatterns in the genus Peperomia (Piperaceae). International Journal of Plant Sciences 170(3): 343-354.

    Howarth, D. G. and M. J. Donoghue. 2009. Phylogenetic analysis of the "ECE" (CYC/TB1) clade reveals duplications predating the core eudicots. Proceedings of the National Academy of Sciences 103(24): 9101-9106.

    Howarth, D. G. and M. J. Donoghue. 2009. Duplications and expression of DIVARICATA-like genes in Dipsacales. Molecular Biology and Evolution 26(6): 1245-1258.

    Hu, G.-W., L.-G. Lei, K.-M. Liu, and C.-L. Long. 2009. Floral development in Nymphaea tetragona (Nymphaeaceae). Botanical Journal of the Linnaean Society 159(2): 211-221.

    Igersheim, A., M. Buzgo, and P. K. Endress. 2001. Gynoecium diversity and systematics in basal monocots. Botanical Journal of the Linnaean Society 136(1): 1-65.

    Irish, V. F. 2006. Duplication, diversification, and comparative genetics of angiosperm MADS-Box genes. Pp. 129-161 In: D. E. Soltis, J. H. Leebens-Mack, P. S. Soltis (eds.), Vol. 44, Advances in Botanical Research, Developmental Genetics of the Angiosperm Flower. Amsterdam: Elsevier.

    Jaillon, C. O., J.-M. Aury, B. Noel, A. Policriti, C. Clepet, A. Casagrande, N. Choisne, S. Aubourg, N. Vitulo, C. Jubin, A. Vezzi, F. Legeai, P. Hugueney, C. Dasilva, D. Horner, E. Mica, D. Jublot, J. Poulain, C. Bruyère, A. Billault, B. Segurens, M. Gouyvenoux, E. Ugarte, F. Cattonaro, V. Anthouard, V. Vico, C. Del Fabbro, M. Alaux, G. Di Gaspero, V. Dumas, N. Felice, S. Paillard, I. Juman, M. Moroldo, S. Scalabrin, A. Canaguier, I. Le Clainche, G. Malacrida, E. Durand, G. Pesole, V. Laucou, P. Chatelet, D. Merdinoglu, M. Delledonne, M. Pezzotti, A. Lecharny, C. Scarpelli, F. Artiguenave, M. E. Pè, G. Valle, M. Morgante, M. Caboche, A.-F. Adam-Blondon, J. Weissenbach, F. Quétier, and P. Wincker. 2007. The grapevine genome sequence suggests ancestral hexaploidization in major angiosperm phyla. Nature 449: 463-467.

    Jain, R. K. 1963. Studies in Musaceae- 1. Musa cardiosperma sp. nov., a fossil banana fruit from the Deccan Intertrappean Series, India. The Palaeobotanist 12: 45-58.

    Jansen, R. K., Z. Cai, L. A. Raubeson, H. Daniell, C. W. dePamphilis, J. Leebens-Mack, K. F. Müller, M. Guisinger-Bellian, R. C. Haberle, A. K. Hansen, T. W. Chumley, S.-B. Lee, R. Peery, J. R. McNeal, J. V. Kuehl, and J. L. Boore. 2007. Analysis of 81 genes from 64 plastid genomes resolves relationships in angiosperms and identifies genome-scale evolutionary patterns. Proceedings of the National Academy of Sciences 104(49): 19369-19374.

    Jansen, R. K., C. Saski, S.-B. Lee, A. K. Hansen, and H. Daniell. 2011. Complete plastid genome sequences of three rosids (Castanea, Prunus, Theobroma): evidence for at least two independent transfers of rpl22 to the nucleus. Molecular Biology and Evolution 28(1): 835-847.

    Janssen, T. and K. Bremer. 2004. The age of major monocot groups inferred from 800+ rbcL sequences. Botanical Journal of the Linnaean Society 146(4): 385-398.

    Jaramillo, M. A., R. Callejas, C. Davidson, J. F. Smith, A. C. Stevens, and E. J. Tepe. 2008. A phylogeny of the tropical genus Piper using ITS and the chloroplast intron psbJ-petA. Systematic Botany 33(4): 647-660.

    Jarzen, D. M. 1980. The occurrence of Gunnera pollen in the fossil record. Biotropica 12(2): 117-123.

    Jarzen, D. M. 1983. The fossil pollen record of the Pandanaceae. Bulletin of the Singapore Botanical Garden 36(2): 163-175.

    Jian, S., P. S. Soltis, M. A. Gitzendanner, M. J. Moore, R. Li, T. A. Hendry, Y.-L. Qiu, A. Dhingra, C. D. Bell, and D. E. Soltis. 2008. Resolving an ancient, rapid radiation in Saxifragales. Systematic Biology 57(1): 38-57.

    Jiao, Y., N. L. Wickett, S. Ayyampalayam, A. S. Chanderbali, L. Landherr, P. E. Ralph, L. P. Tomsho, Y. Hu, H. Liang, P. S. Soltis, D. E. Soltis, S. W. Clifton, S. E. Schlarbaum, S. C. Schuster, H. Ma, J. Leebens-Mack, and C. W. dePamphilis. 2011. Ancestral polyploidy in seed plants and angiosperms. Nature 473(7345): 97-100.

    Judd, W. S. and R. G. Olmstead. 2004. A survey of tricolpate (eudicot) phylogenetic relationships. American Journal of Botany 91(10): 1627-1644.

    Keller, J. A., P. S. Herendeen, and P. R. Crane. 1996. Fossil flowers and fruits of the Actinidiaceae from the Campanian (late Cretaceous) of Georgia. American Journal of Botany 83(4): 528-541.

    Kerp, J. H. F. 1983. Aspects of Permian palaeobotany and palynology. V. Sobernheimia jonkeri nov. gen., nov. sp. a new fossil plant of cycadalean affinity from the Waderner Gruppe of Sobernheim. Review of Palaeobotany and Palynology 38: 173-183.

    Kim, J.-H., D.-K. Kim, F. Forest, M. F. Fay, and M. W. Chase. 2010. Molecular phylogenetics of Ruscaceae sensu lato and related families (Asparagales) based on plastid and nuclear DNA sequences. Annals of Botany 106(5): 775-790.

    Kim, J.-Y., Z. Yuan, and D. Jackson. 2003. Developmental regulation and significance of KNOX protein trafficking in Arabidopsis. Development 130: 4351-4362.

    Kim, S., J. Koh, M. Jeong, H. Kong, Y. Hu, H. Ma, P. S. Soltis, and D. E. Soltis. 2005. Expression of MADS-box genes in basal angiosperms: implications for the evolution of floral regulators. The Plant Journal 43: 724-744.

    Kim, S., J. Koh, H. Ma, Y. Hu, P. K. Endress, B. A. Hauser, M. Buzgo, P. S. Soltis, and D. E. Soltis. 2005. Sequence and expression studies of A-, B-, and E-class MADS-box homologues in Eupomatia (Eupomatiaceae): support for the bracteate origin of the calyptra. International Journal of Plant Sciences 166(2): 185-198.

    Kim, S., D. E. Soltis, P. S. Soltis, M. J. Zanis, and Y. Suh. 2004. Phylogenetic relationships among early-diverging eudicots based on four genes: were the eudicots ancestrally woody? Molecular Phylogenetics and Evolution 31(1): 16-30.

    Kimoto, Y. and H. Tobe. 2001. Embryology of Laurales: a review and perspectives. Journal of Plant Research 114(3): 247-267.

    Kimoto, Y. and H. Tobe. 2008. Embryology of Hortonioideae and Monimioideae (Monimiaceae, Laurales): characteristics of the 'lower' monimioids. Botanical Journal of the Linnaean Society 158(2): 228-241.

    Kirchoff, B. K., L. P. Lagomarsino, W. H. Newman, M. E. Bartlett, and C. D. Specht. 2009. Early floral development of Heliconia latispatha (Heliconiaceae), a key taxon for understanding the evolution of flower development in the Zingiberales. American Journal of Botany 93(3): 580-593.

    Knobloch, E. and D. H. Mai. 1986. Monographie der fructhe und samen in der Kreide der Mitteleuropa. Edice Rozprovy ustredniho ustavu Geologickeho 47: 1-219.

    Klavins, S. D., T. N. Taylor, and E. L. Taylor. 2002. Anatomy of Umkomasia (Corystospermales) from the Triassic of Antarctica. American Journal of Botany 89(4): 664-676.

    Korotkova, N., J. V. Schneider, D. Quandt, A. Worberg, G. Zizka, and T. Borsch. 2009. Phylogeny of the eudicot order Malpighiales: analysis of a recalcitrant clade with sequences of the petD group II intron. Plant Systematics and Evolution 282(3-4): 201-228.

    Kramer, E. M. 2009. Aquilegia: a new model for plant development, ecology, and evolution. Annual Review of Plant Biology 60: 261-277.

    Krassilov, V. A. and L. B. Golovneva. 2004. A minute mid-Cretaceous flower from Siberia and implications for the problem of basal angiosperms. Geodiversitas 26(1): 5-15.

    Krassilov, V., Z. Lewy, and E. Nevo. 2004. Controversial fruit-like remains from the Lower Cretaceous of the Middle East. Cretaceous Research 25: 697-707.

    Krassilov, V. and B. Pacltova. 1989. Asterocelastrus cretacea, a mid-Cretaceous angiosperm from Bohemia. Review of Palaeobotany and Palynology 60: 1-6.

    Krassilov, V. A., P. V. Shilin, and V. A. Vachrameev. 1983. Cretaceous flowers from Kazakstan. Review of Palaeobotany and Palynology 40: 91-113.

    Kvaček, J. and H. Eklund. 2003. A report on newly recovered reproductive structures from the Cenomanian of Bohemia (central Europe). International Journal of Plant Sciences 164(6): 1021-1039.

    Kvaček, J. and E. M. Friis. 2010. Zlatkocarpus gen. nov., a new angiosperm reproductive structure with monocolpate-reticulate pollen from the late Cretaceous (Cenomanian) of the Czech Republic. Grana 49(2): 115-127.

    Labandeira, C. C. 2000. The paleobiology of pollination and its precursors. Pp. 233-269 In: R. A. Gastaldo and W. A. DiMichele (eds.), Phanerozoic Terrestrial Ecosystems. Paleontological Society Papers 6: 233-269.

    Leebens-Mack, J., L. A. Raubeson, L. Cui, J. V. Kuehl, M. H. Fourcade, T. W. Chumley, J. L. Boore, R. K. Jansen, and C. W. dePamphilis. 2005. Identifying the basal angiosperm node in chloroplast genome phylogenies: sampling one's way out of the Felsenstein Zone. Molecular Biology and Evolution 22(10): 1948-1963.

    Leng, Q. and E. M. Friis. 2006. Angiosperm leaves associated with Sinocarpus infructescences from the Yixian Formation (mid-Early Cretaceous) of NE China. Plant Systematics and Evolution 262(3/4): 173-187.

    Leng, Q., J. Schonenberger, and E. M. Friis. 2005. Late Cretaceous follicular fruits from southern Sweden with systematic affinities to early diverging eudicots. Botanical Journal of the Linnaean Society 148: 377-407.

    Les, D. H., M. L. Moody, A. S. Dorn, and W. E. Phillips. 2004. A genetically confirmed intersubgeneric hybrid in Nymphaea L. (Nymphaeaceae Salisb.). HortScience 39(2): 219-222.

    Leseberg, C. H. and M. R. Duvall. 2009. The complete chloroplast genome of Coix lacryma-jobi and a comparative molecular evolutionary analysis of plastomes in cereals. Journal of Molecular Evolution 69(4): 311-318.

    Li, G. S., Z. Meng, H. Z. Kong, Z. D. Chen, G. Theißen, and A. M. Lu. 2005. Characterization of candidate class A, B, and E floral homeotic genes from the perianthless basal angiosperm Chloranthus spicatus (Chloranthaceae). Development, Genes and Evolution 215(9): 437.

    Li, H. 2005. Early Cretaceous sarraceniacean-like pitcher plants from China. Acta Botanica Gallica 152(2): 227-234.

    Li, J.-K. and S.-Q. Huang. 2009. Flower thermoregulation facilitates fertilization in Asian sacred lotus. Annals of Botany 103(7): 1159-1163.

    Li, J.-K. and S.-Q. Huang. 2009. Effective pollinators of Asian sacred lotus (Nelumbo nucifera): contemporary pollinators may not reflect the historical pollination syndrome. Annals of Botany 104(5): 845-851.

    Li, R.-Q., Z.-D. Chen, A.-M. Lu, D. E. Soltis, P. S. Soltis, and P. S. Manos. 2004. Phylogenetic relationships in Fagales based on DNA sequences from three genomes. International Journal of Plant Sciences 165(2): 311-324.

    Liang, H., A. Barakat, S. E. Schlarbaum, and J. E. Carlson. 2011. Organization of the chromosome region harboring a FLORICAULA/LEAFY gene in Liriodendron. Tree Genetics and Genomes 7(2): 373-384.

    Liang, H., J. E. Carlson, J. H. Leebens-Mack, P. K. Wall, L. A. Mueller, M. Buzgo, L. L. Landherr, Y. Hu, D. S. DiLoreto, and D. C. Ilut et al.. 2008. An EST database for Liriodendron tulipifera floral buds: the first EST resource for functional and comparative genomics in Liriodendron. Tree Genetics and Genomes 4(3): 419-433.

    Liang, H., E. G. Fang, J. P. Tomkins, M. Luo, D. Kudrna, H. R. Kim, K. Arumuganathan, S. Zhao, J. H. Leebens-Mack, and S. E. Schlarbaum et al.. 2007. Development of a BAC library for yellow-poplar (Liriodendron tulipifera) and the identification of genes associated with flower development and lignin biosynthesis. Tree Genetics and Genomes 3(3): 215-225.

    Liao, P.-C., D.-C. Kuo, C.-C. Lin, K.-C. Ho, T.-P. Lin, and S.-Y. Hwang. 2010. Historical spatial range expansion and a very recent bottleneck of Cinnamomum kanehirae Hay. (Lauraceae) in Taiwan inferred from nuclear genes. BMC Evolutionary Biology 10: 124.

    Linder, H. P., P. Eldenas, and B. G. Briggs. 2007. Contrasting patterns of radiation in African and Australian Restionaceae. Evolution 57(12): 2688-2702.

    Litt, A. and V. F. Irish. 2003. Duplication and diversification in the APETALA/FRUITFULL floral homeotic gene lineage: implications for the evolution of floral development. Genetics 165: 821-833.

    Liu, C., J. Zhang, N. Zhang, H. Shan, K. Su, J. Zhang, Z. Meng, H. Kong, and Z. Chen. 2010. Interactions among proteins of floral MADS-Box genes in basal eudicots: implications for evolution of the regulatory network for flower development. Molecular Biology and Evolution 27(7): 1598-1611.

    Lloyd, G. T., K. E. Davis, D. Pisani, J. E. Tarver, M. Ruta, M. Sakamoto, D. W. E. Hone, R. Jennings, and M. J. Benton. 2008. Dinosaurs and the Cretaceous terrestrial revolution. Proceedings of the Royal Society of London, Series B, Biological Sciences 275(1650): 2483-2490.

    Loconte, H. and D. W. Stevenson. 1991. Cladistics of the Magnoliidae. Cladistics 7: 267-296.

    Löhne, C., T. Borsch, and J. H. Wiersema. 2007. Phylogenetic analysis of Nymphaeales using fast-evolving and noncoding chloroplast markers. Botanical Journal of the Linnaean Society 154(2): 141-163.

    Löhne, C., M.-J. Yoo, T. Borsch, J. H. Wiersema, V. Wilde, C. D. Bell, W. Barthlott, D. E. Soltis, and P. S. Soltis. 2008. Biogeography of Nymphaeales: extant patterns and historical events. Taxon 57(4): 1123-1146.

    Lora, J., M. Herrero, and J. I. Hormaza. 2009. The coexistence of bicellular and tricellular pollen in Annona cherimola (Annonaceae): implications for pollen evolution. American Journal of Botany 96(4): 802-808.

    Luna-Vega, I. and S. Magallón. 2010. Phylogenetic composition of angiosperm diversity in the cloud forests of Mexico. Biotropica 42(4): 444-454.

    Lupia, R., P. S. Herendeen, and J. A. Keller. 2002. A new fossil flower and associated coprolites: evidence for angiosperm-insect interactions in the Santonian (late Cretaceous) of Georgia, USA. International Journal of Plant Sciences 163(4): 675-686.

    Lyew, J., Z. Li, Y. Liang-Chen, L. Yi-bo, and T. L. Sage. 2007. Pollen tube growth in association with a dry-type stigmatic transmitting tissue and extragynoecial compitum in the basal angiosperm Kadsura longipedunculata (Schisandraceae). American Journal of Botany 94(7): 1170-1182.

    Maciunas, E., J. G. Conran, J. M. Bannister, R. Paull, and D. E. Lee. 2011. Miocene Astelia (Asparagales, Asteliaceae) macrofossils from southern New Zealand. Australian Systematic Botany 24(1): 19-31.

    Madrid, E. N. and W. E. Friedman. 2008. Female gametophyte development in Aristolochia labiata Willd. (Aristolochiaceae). Botanical Journal of the Linnaean Society 158(1): 19-29.

    Magallón, S. 2009. Flowering plants (Magnoliophyta). Pp. 161-212 In: S. B. Hedges and S. Kumar (eds.), The Timetree of Life. Oxford: Oxford University Press, 551 pp.

    Magallón, S. 2010. Using fossils to break long branches in molecular dating: a comparison of relaxed clocks applied to the origin of angiosperms. Systematic Biology 59(4): 384-399.

    Magallón, S. and A. Castillo. 2009. Angiosperm diversification through time. American Journal of Botany 96(1): 349-365.

    Magallón, S., P. R. Crane, and P. S. Herendeen. 1999. Phylogenetic pattern, diversity, and diversification of eudicots. Annals of the Missouri Botanical Garden 86: 297-372.

    Magallón, S., P. S. Herendeen, and P. R. Crane. 2001. Androdecidua endressii gen. et sp. nov., from the late Cretaceous of Georgia (United States): further floral diversity of Hamamelidoideae (Hamamelidaceae). International Journal of Plant Sciences 161(Supplement 6): S41-S55.

    Magallón-Puebla, S., P. S. Herendeen, and P. R. Crane. 1997. Quadriplatanus georgianus gen. et sp. nov.: staminate and pistillate platanaceous flowers from the late Cretaceous (Coniacian-Santonian) of Georgia, U.S.A. International Journal of Plant Sciences 162(4): 963-983.

    Magallón-Puebla, S., P. S. Herendeen, and P. K. Endress. 1996. Allonia decandra: floral remains of the tribe Hamamelideae (Hamamelidaceae) from Campanian strata of southeastern USA. Plant Systematics and Evolution 202: 177-198.

    Manchester, S. R. 1987. The fossil history of Juglandaceae. Monographs in Systematic Botany from the Missouri Botanical Garden, 137 pp.

    Manchester, S. R. and W. J. Kress. 1993. Fossil bananas (Musaceae): Ensete oregonense sp. nov. from the Eocene of western North America and its phytogeographic significance. American Journal of Botany 80(11): 1264-1272.

    Manchester, S. R., T. M. Lehman, and E. A. Wheeler. 2010. Fossil palms (Arecaceae, Coryphoideae) associated with juvenile herbivorous dinosaurs in the Upper Cretaceous Aguja Formation, Big Bend National Park, Texas. International Journal of Plant Sciences 171(6): 679-689.

    Manos, P. S., P. S. Soltis, D. E. Soltis, S. R. Manchester, S.-H. Oh, C. D. Bell, D. L. Dilcher, and D. E. Stone. 2007. Phylogeny of extant and fossil Juglandaceae inferred from the integration of molecular and morphological data sets. Systematic Biology 56(3): 412-430.

    Mardanov, A. V., N. V. Ravin, B. B. Kuznetsov, T. H. Samigullin, A. S. Antonov, T. V. Kolganova, and K. G. Skyabin. 2008. Complete sequence of the duckweed (Lemna minor) chloroplast genome: structural organization and phylogenetic relationships to other angiosperms. Journal of Molecular Evolution 66(6): 555-564.

    Marmi, J., B. Gomez, C. Martín-Closas, and S. Villalba-Breva. 2010. A reconstruction of the fossil palm Sabalites longirhachis (Unger) J. Kvaček et Herman from the Maastrichtian of Pyrenees. Review of Palaeobotany and Palynology 163(1-2): 73-83.

    Marquínez, X., L. G. Lohmann, M. L. Faria Salatino, A. Salatino, and F. González. 2009. Generic relationships and dating of lineages in Winteraceae based on nuclear (ITS) and plastid (rpS16 and psbA-trnH) sequence data. Molecular Phylogenetics and Evolution 53(2): 435-449.

    Martínez-Míllan, M. 2010. Fossil record and age of the Asteridae. The Botanical Review 76(1): 83-135.

    Martínez-Míllan, M., W. L. Crepet, and K. C. Nixon. 2009. Pentapetalum trifasciculandricus gen. et sp. nov., a thealean fossil flower from the Raritan Formation, New Jersey, USA (Turonian, late Cretaceous). American Journal of Botany 96(5): 933-949.

    Maslova, N. P. 2010. Systematics of fossil platanoids and hamamelids. Paleontologicheskii Zhurnal 44(11): 1379-1466.

    Mathews, M. L. and P. K. Endress. 2006. Floral structure and systematics in four orders of rosids, including a broad survey of floral mucilage cells. Plant Systematics and Evolution 260(2-4): 199-221.

    Mathews, S. and M. J. Donoghue. 2000. Basal angiosperm phylogeny inferred from duplicate phytochromes A and C. International Journal of Plant Sciences 161(Supplement 6): S41-S55.

    McElwain, J. C., K. J. Willis, and R. Lupia. 2005. Chapter 7. Cretaceous CO2 decline and the radiation and diversification of angiosperms. Pp. 133-165 In: J. R. Ehleringer, T. E. Cerling, and M.-D. Dearing, A History of Atmospheric CO2 and its Effects on Plants, Animals, and Ecosystems. New York: Springer, 530 pp.

    McLoughlin, S., R. J. Carpenter, G. J. Jordan, and R. S. Hill. 2008. Seed ferns survived the end-Cretaceous mass extinction in Tasmania. American Journal of Botany 95(4): 465-471.

    McLoughlin, S., R. J. Carpenter, and C. Pott. 2011. Ptilophyllum muelleri (Ettingsh.) comb. nov. from the Oligocene of Australia: last of the Bennettitales? International Journal of Plant Sciences 172(4): 574-585.

    Melzer, R., Y.-Q. Wang, and G. Theißen. 2010. The naked and the dead: the ABCs of gymnosperm reproduction and the origin of the angiosperm flower. Seminars in Cell & Developmental Biology 21(1): 118-128.

    Michelangeli, F. A., J. I. Davis, and D. Wm. Stevenson. 2003. Phylogenetic relationships among Poaceae and related families as inferred from morphology, inversions in the plastid genome, and sequence data from the mitochondrial and plastid genomes. American Journal of Botany 90(1): 93-106.

    Miki, A. 1977. Late Cretaceous pollen and spore floras of northern Japan: composition and interpretation. Journal of the Faculty of Science, Hokkaido University, Series IV. Geology and Mineralogy 17: 399-436.

    Miller, J. M. 1988. A new species of Degeneria (Degeneriaceae) from Fiji Archipelago. Journal of the Arnold Arboretum 69: 275-280.

    Miller, J. M. 1989. The archaic flowering plant family Degeneriaceae: its bearing on an old enigma. National Geographic Research 5(2): 218-231.

    Mohr, B. A. R. and M. E. C. Bernardes-de-Oliveira. 2004. Endressinia brasiliana, a magnolialean angiosperm from the Lower Cretaceous Crato Formation (Brazil). International Journal of Plant Sciences 165(6): 1121-1133.

    Mohr, B. A. R., M. E. C. Bernardes-de-Oliveira, E. C. Mary, and D. W. Taylor. 2008. Pluricarpellatia, a nymphaealean angiosperm from the lower Cretaceous of northern Gondwana (Crato Formation, Brazil). Taxon 57(4): 1147-1158.

    Mohr, B. A. R. and H. Eklund. 2003. Araripia florifera, a magnoliid angiosperm from the Lower Cretaceous Crato Formation (Brazil). Review of Palaeobotany and Palynology 126: 279-292.

    Moiseva, M. G. 2011. New species of the genus Macclintockia (angiosperms) from the Campanian of Ugol'naya Bay (northeastern Russia). Paleontologicheskii Zhurnal 45(2): 207-223.

    Moore, M. J., C. D. Bell, P. S. Soltis, and D. E. Soltis. 2007. Using plastid genome-scale data to resolve enigmatic relationships among basal angiosperms. Proceedings of the National Academy of Sciences 104(49): 19363-19368.

    Moore, M. J., P. S. Soltis, C. D. Bell, J. G. Burleigh, and D. E. Soltis. 2010. Phylogenetic analysis of 83 plastid genes further resolves the early diversification of eudicots. Proceedings of the National Academy of Sciences 107(10): 4623-4628.

    Morris, A. B., C. D. Bell, J. W. Clayton, W. S. Judd, D. E. Soltis, and P. S. Soltis. 2007. Phylogeny and divergence time estimation in Illicium with implications for New World biogeography. Systematic Botany 32(2): 236-249.

    Morton, C. M. 2011. Newly sequenced nuclear gene (Xdh) for inferring angiosperm phylogeny. Annals of the Missouri Botanical Garden 98(1): 63-89.

    Müller, J. 1981. Fossil pollen records of extant angiosperms. Botanical Review (Lancaster): 47: 1-146.

    Müller, J. 1984. Significance of fossil pollen for angiosperm history. Annals of the Missouri Botanical Garden 71: 419-443.

    Nadot, S., C. A. Furness, J. Sannier, L. Penet, S. Triki-Teurtroy, B. Albert, and A. Ressayre. 2008. Phylogenetic comparative analysis of microsporogenesis in angiosperms with a focus on monocots. American Journal of Botany 95(11): 1426-1436.

    Narita, A., T. Yamada, and M. Matsumoto. 2008. Platanoid leaves from Cenomanian to Turonian Mikasa Formation, northern Japan and their modes of occurrence. Paleontological Research 12(1): 81-88.

    Nichols, D. J. and S. R. Jacobson. 1982. Palynostratigraphic framework for the Cretaceous (Albian-Maastrichtian) of the overthrust belt of Utah and Wyoming. Palynology 6: 119-147.

    Nie, Z.-L., H. Sun, H. Li, and J. Wen. 2006. Intercontinental biogeography of subfamily Orontioideae (Symplocarpus, Lysichiton, and Orontium) of Araceae in eastern Asia and North America. Molecular Phylogenetics and Evolution 40(1): 155-165.

    Nie, Z.-L., J. Wen, H. Azuma, Y-L. Qiu, H. Sun, Y. Meng, W-B. Sun, and E. A. Zimmer. 2008. Phylogenetic and biogeographic complexity of Magnoliaceae in the Northern Hemisphere inferred from three nuclear data sets. Molecular Phylogenetics and Evolution 48(3): 1027-1040.

    Nishida, H. 1994. Elsemaria, a late Cretaceous angiosperm fructification from Hokkaido, Japan. Plant Systematics and Evolution (Supplement) 8: 123-135.

    Nishida, H. and M. Nishida. 1988. Protomonimia kasai-nakajhongii gen. et. sp. nov.: a permineralized magnolialean fructification from the mid-Cretaceous of Japan. The Botanical Magazine 101: 397-426.

    Nishida, M., T. Ohsawa, T. Nishida, A. Yoshida, and Y. Kanie. 1996. A permineralized magnolialean fructification from the Upper Cretaceous of Hokkaido, Japan. Research Institute Evolutionary Biology Scientific Report 8: 19-30.

    Nixon, K. C. 2008. Paleobotany, evidence, and molecular dating: an example from the Nymphaeales. Annals of the Missouri Botanical Garden 95(1): 43-50.

    Nixon, K. C. and W. L. Crepet. 1993. Late Cretaceous fossil flowers of ericalean affinity. American Journal of Botany 80(6): 616-623.

    Oakley, D. and H. J. Falcon-Lang. 2009. Morphometric analysis of Cretaceous (Cenomanian) angiosperm woods from the Czech Republic. Review of Palaeobotany and Palynology 153(3-4): 375-385.

    Oelschlägel, B., S. Gorb, S. Wanke, and C. Neinhus. 2009. Structure and biomechanics of trapping flower trichomes and their role in the pollination biology of Aristolochia plants (Aristolochiaceae). New Phytologist 184(4): 988-1002.

    Oginuma, K. and H. Tobe. 2006. Chromosome evolution in the Laurales based on analyses of original and published data. Journal of Plant Research 119(4): 309-320.

    Oh, S.-H. and P. S. Manos. 2008. Molecular phylogenetics and cupule evolution in Fagaceae as inferred from nuclear CRABS CLAW sequences. Taxon 57(2): 434-451.

    Ohana, T., T. Kimura, and S. Chitaley. 1999. Keraocarpon gen. nov., magnolialean fruits from the Upper Cretaceous of Hokkaido, Japan. Paleontological Research 3: 294-302.

    Oppel, S. and A. L. Mack. 2010. Bird assemblage and visitation pattern at fruiting Elmerrillia tsiampaca (Magnoliaceae) trees in Papua New Guinea. Biotropica 42(2): 229-235.

    Page, V. M. 1967. Angiosperm wood from the Upper Cretaceous of central California: Part 1. American Journal of Botany 54(4): 510-514.

    Pan, A. D., B. F. Jacobs, J. Dransfield, and W. J. Baker. 2006. The fossil history of palms (Arecaceae) in Africa and new records from the Late Oligocene (28-27 MYA) of north-western Ethiopia. Botanical Journal of the Linnean Society 151(1): 69-81.

    Parkinson, C. L., K. L. Adams, and J. D. Palmer. 1999. Multigene analyses identify the three earliest lineages of extant flowering plants. Current Biology 9(24): 1485-1491.

    Paterson, A. H., J. E. Bowers, R. Bruggmann, I. Dubchak, J. Grimwood, H. Gundlach, G. Haberer, U. Hellsten, T. Mitros, A. Poliakov, J. Schmutz, M. Spannagl, H. Tang, X. Wang, T. Wicker, A. K. Bharti, J. Chapman, F. A. Feltus, U. Gowik, I. V. Grigoriev, E. Lyons, C. A. Maher, M. Martis, A. Narechania, R. P. Otillar, B. W. Penning, A. A. Salamov, Y. Wang, L. Zhang, N. C. Carpita, M. Freeling, A. R. Gingle, C. T. Hash, B. Keller, P. Klein, S. Kresovich, M. C. McCann, R. Ming, D. G. Peterson, Mehboob-ur-Rahman, D. Ware, P. Westhoff, K. F. X. Mayer, J. Messing, and D. S. Rokhsar. 2009. The Sorghum bicolor genome and the diversification of grasses. Nature 457: 551-556.

    Pedersen, K. R., M. von Balthazar, P. R. Crane, and E. M. Friis. 2007. Early Cretaceous floral structures and in situ tricolpate-striate pollen: new early eudicots from Portugal. Grana 46(3): 176-196.

    Pedersen, K. R., P. R. Crane, A. N. Drinnan, and E. M. Friis. 1991. Fruits from the mid-Cretaceous of North America with pollen grains of the Clavatipollenites type. Grana 30: 577-590.

    Pedersen, K. R., P. R. Crane, E. M. Friis, and A. N. Drinnan. 1994. Reproductive structures of an extinct platanoid from the early Cretaceous (latest Albian) of eastern North America. Review of Palaeobotany and Palynology 80: 291-303.

    Pellmyr, O., L. B. Thien, G. Bergström, and I. Groth. 1990. Pollination of New Caledonian Winteraceae: opportunistic shifts or parallel radiation with their pollinators? Plant Systematics and Evolution 173(3-4): 143-157.

    Penny, J. H. J. 1988. Early Cretaceous acolumellate semitectate pollen from Egypt. Palaeontology 31: 373-418.

    Podoplelova, Y. and G. Ryzhakov. 2005. Phylogenetic analysis of the order Nymphaeales based on the nucleotide sequences of the chloroplast ITS2-4 region. Plant Science 169(3): 606-611.

    Poinar, G., Jr. and K. L. Chambers. 2005. Palaeoanthella huangii gen. and sp. nov., an early Cretaceous flower (Angiospermae) in Burmese amber. Sida 21(4): 2087-2092.

    Poinar, G., Jr., K. L. Chambers, and R. Buckley. 2007. Eoepigynia burmensis gen. and sp. nov., an early Cretaceous eudicot flower (Angiospermae) in Burmese amber. Journal of the Botanical Research Institute of Texas 1(1): 91-96.

    Poole, I. and J. Francis. 2000. The first record of fossil wood of Winteraceae from the Upper Cretaceous of Antarctica. Annals of Botany 85: 307-315.

    Poole, I. J., D. J. Cantrill, P. Hayes, and J. Francis. 2000. The fossil record of Cunoniaceae: new evidence from Late Cretaceous wood of Antarctica. Review of Paleobotany and Palynology 111(1-2): 127-144.

    Posluszny, U. and P. B. Tomlinson. 2003. Aspects of inflorescence and floral development in the putative basal angiosperm Amborella trichopoda (Amborellaceae). Canadian Journal of Botany 81(1): 28-39.

    Preston, J. C., A. Christensen, S. T. Malcomber, and E. A. Kellogg. 2009. MADS-box gene expression and implications for developmental origins of the grass spikelet. American Journal of Botany 96(8): 1419-1429.

    Preston, J. C. and E. A. Kellogg. 2007. Conservation and divergence of APETALA1/FRUITFULL-like gene function in grasses: evidence from gene expression analysis. The Plant Journal 52(1): 69-81.

    Preston, J. C., C. C. Martinez, and L. C. Hileman. 2011. Gradual disintegration of the floral symmetry gene network is implicated in the evolution of a wind pollination syndrome. Proceedings of the National Academy of Sciences 108(6): 2343-2348.

    Prigge, M. J. and S. E. Clark. 2006. Evolution of the class III HD-Zip family in land plants. Evolution and Development 8(4): 350-361.

    Prychid, C. J., D. D. Sokoloff, M. V. Remizowa, R. E. Tuckett, S. R. Yadav, and P. J. Rudall. 2011. Unique stigmatic hairs and pollen-tube growth within the stigmatic cell wall in the early divergent angiosperm family Hydatellaceae. Annals of Botany 108(4): 599-608.

    Qiu, Y.-L., M. W. Chase, D. H. Les, and C. R. Parks. 1993. Molecular phylogenetics of the Magnoliidae: cladistic analysis of nucleotide sequences of the plastid gene rbcL. Annals of the Missouri Botanical Garden 80: 587-606.

    Qiu, Y.-L., O. Dombrovska, J. Lee, L. Li, B. A. Whitlock, F. Bernasconi-Quadroni, J. S. Rest, C. C. Davis, T. Borsch, K. W. Hilu, S. S. Renner, D. E. Soltis, P. S. Soltis, M. J. Zanis, J. J. Cannone, R. R. Gutell, M. Powell, V. Savolainen, L. W. Chatrou, and M. W. Chase. 2005. Phylogenetic analyses of basal angiosperms based on nine plastid, mitochondrial, and nuclear genes. International Journal of Plant Sciences 166(5): 815-842.

    Qiu, Y.-L., J. Lee, F. Bernasconi-Quadroni, D. E. Soltis, P. S. Soltis, M. Zanis, E. A. Zimmer, Z. Chen, V. Savolainen, and M. W. Chase. 2000. Phylogeny of basal angiosperms: analyses of five genes from three genomes. International Journal of Plant Sciences 161(Supplement 6): S3-S27.

    Qiu, Y.-L., J. Lee, B. A. Whitlock, F. Bernasconi-Quadroni, and O. Dombrovska. 2001. Was the ANITA rooting of the angiosperm phylogeny affected by long-branch attraction? Molecular Biology and Evolution 18: 1745-1753.

    Qiu, Y.-L., L. Li, T. A. Hendry, R. Li, D. W. Taylor, M. J. Issa, A. J. Ronen, M. L. Vekaria, and A. M. White. 2006. Reconstructing the basal angiosperm phylogeny: evaluating information content of mitochondrial genes. Taxon 55(4): 837-856.

    Ramanujam, C. G. K. 2004. Palms through ages in southern India - a reconnaissance. The Palaeobotanist 53: 1-4.

    Ramírez, S. R., T. Eltz, M. K. Fujiwara, G. Gerlach, B. Goldman-Huertas, N. D. Tsutsui, and N. E. Pierce. 2011. Asynchronous diversification in a specialized plant-pollinator mutualism. Science 333(6050): 1742-1746.

    Ramírez, S. R., B. Gravendeel, R. B. Singer, C. R. Marshall, and N. E. Pierce. 2007. Dating the origin of the Orchidaceae from a fossil orchid with its pollinator. Nature 448(7157): 1042-1045.

    Rasmussen, D. A., E. M. Kramer, and E. A. Zimmer. 2009. One size fits all? Molecular evidence for a commonly inherited petal identity program in Ranunculales. American Journal of Botany 96(1): 96-109.

    Reardon, W., D. A. Fitzpatrick, M. A. Fares, and J. M. Nugent. 2009. Evolution of flower shape in Plantago lanceolata. Plant Molecular Biology 71(3): 241-250.

    Ree, R. H. and M. J. Donoghue. 1999. Inferring rates of change in flower symmetry in asterid angiosperms. Systematic Biology 48: 633-641.

    Remizowa, M. V., D. D. Sokoloff, T. D. Macfarlane, S. R. Yadav, C. J. Prychid, and P. J. Rudall. 2008. Comparative pollen morphology in the early-divergent angiosperm family Hydatellaceae reveals variation at the infraspecific level. Grana 47(2): 81-100.

    Remizowa, M. V., D. D. Sokoloff, and P. J. Rudall. 2011. Evolutionary history of the monocot flower. Annals of the Missouri Botanical Garden 97(4): 617-645.

    Ren, Y., H.-F. Li, L. Zhao, and P. K. Endress. 2007. Floral morphogenesis in Euptelea (Eupteleaceae, Ranunculales). Annals of Botany 100(2): 185-193.

    Renner, S. S., L.-B. Zhang, and J. Murata. 2004. A chloroplast phylogeny of Arisaema (Araceae) illustrates Tertiary floristic links between Asia, North America, and East Africa. American Journal of Botany 91(6): 881-888.

    Retallack, G. J. and D. L. Dilcher. 1981. Early angiosperm reproduction: Prisca reynoldsii, gen. et sp. nov. from the mid-Cretaceous coastal deposits in Kansas, USA. Palaeontographica B 179: 103-137.

    Reveal, J. L. 1995. Newly required suprageneric names in vascular plants. Phytologia 79(2): 68-76.

    Rohwer, J. G., J. Li, B. Rudolph, S. A. Schmidt, H. Van der Werff, and H.-W. Li. 2009. Is Persea (Lauraceae) monophyletic? Evidence from nuclear ribosomal ITS sequences. Taxon 58(4): 1153-1167.

    Ronse De Craene, L. P. 2007. Are petals sterile stamens or bracts? The origin and evolution of petals in the core eudicots. Annals of Botany 100(3): 621-630.

    Ronse De Craene, L. P. 2008. Homology and evolution of petals in the core eudicots. Systematic Botany 33(2): 301-325.

    Ronse De Craene, L. P., P. S. Soltis, and D. E. Soltis. 2003. Evolution of floral structures in basal angiosperms. International Journal of Plant Sciences 164(Supplement 5): S329-S363.

    Rothwell, G. W., W. L. Crepet, and R. A. Stockey. 2009. Is the anthophyte hypothesis alive and well? New evidence from the reproductive structures of Bennettitales. American Journal of Botany 96(1): 296-322.

    Rudall, P. J., T. Eldridge, J. Tratt, M. M. Ramsey, R. E. Tuckett, S. Y. Smith, M. E. Collinson, M. V. Remizowa, and D. D. Sokoloff. 2009. Seed fertilization, development, and germination in Hydatellaceae (Nymphaeales): implications for endosperm evolution in early angiosperms American Journal of Botany 96(9): 1581-1593.

    Rudall, P. J., M. V. Remizowa, A. S. Beer, E. Bradshaw, D. Wm. Stevenson, T. D. Macfarlane, R. E. Tuckett, S. R. Yadav, and D. D. Sokoloff. 2008. Comparative ovule and megagametophyte development in Hydatellaceae and water lilies reveal a mosaic of features among the earliest angiosperms. Annals of Botany 101(7): 941-956.

    Rudall, P. J., M. V. Remizowa, G. Prenner, C. J. Prychid, R. E. Tuckett, and D. D. Sokoloff. 2009. Nonflowers near the base of extant angiosperms? Spatiotemporal arrangement of organs in reproductive units of Hydatellaceae and its bearing on the origin of the flower. American Journal of Botany 96(1): 67-82.

    Rudall, P. J., D. D. Sokoloff, M. V. Remizowa, J. C. Conran, J. I. Davis, T. D. Macfarlane, and D. W. Stevenson. 2007. Morphology of the Hydatellaceae, an anomalous aquatic family recently recognized as an early-divergent angiosperm lineage. American Journal of Botany 94(7): 1073-1092.

    Saarela, J. M., H. S. Rai, J. A. Doyle, P. K. Endress, S. Matthews, A. D. Marchant, B. G. Briggs, and S. W. Graham. 2007. Hydatellaceae identified as a new branch near the base of the angiosperm phylogenetic tree. Nature 446: 312-315.

    Sage, T. L., K. Hristova-Sarkovski, V. Koehl, J. Lyew, V. Pontieri, P. Bernhardt, P. Weston, S. Bagha, and G. Chiu. 2009. Transmitting tissue architecture in basal-relictual angiosperms: implications for transmitting tissue origins. American Journal of Botany 96(1): 183-206.

    Samain, M.-S., L. Vanderschaeve, P. Chaerle, P. Goetghebeur, C. Neinhuis, and S. Wanke. 2009. Is morphology telling the truth about the evolution of the species rich genus Peperomia (Piperaceae)? Plant Systematics and Evolution 278(1-2): 1-21.

    Samain, M.-S., A. Vrijdaghs, M. Hesse, P. Goetghebeur, F. Rodríguez, A. Stoll, C. Neinhuis, and S. Wanke. 2010. Verhuellia is a segregate lineage in Piperaceae: more evidence from flower, fruit and pollen morphology, anatomy, and development. Annals of Botany 105(5): 677-688.

    Saunders, R. M. K. 2010. Floral evolution in the Annonaceae: hypotheses of homeotic mutations and functional convergence. Biological Reviews 85(3): 571-591.

    Sauquet, H., J. A. Doyle, T. Scharaschkin, T. Borsch, K. W. Hilu, L. W. Chatrou, and A. Le Thomas. 2003. Phylogenetic analysis of Magnoliales and Myristicaceae based on multiple data sets: implications for character evolution. Botanical Journal of the Linnaean Society 142(2): 125-186.

    Schäferhoff, B., Fleischmann, A., Fischer, E., Albach, D. C., T. Borsch, G. Heubl, and K. F. Müller. 2010. Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences. BMC Evolutionary Biology 10: 352.

    Scherer, J., G. Upchurch, and G. Mack. 2006. A new species of Pandanites from the Maastrichtian of south-central New Mexico: implications for the history of Pandanaceae. Abstracts of the Botany 2006 Conference.

    Schneider, E. L., S. Carlquist, and C. B. Hellquist. 2009. Microstructure of tracheids of Nymphaea. International Journal of Plant Sciences 170(4): 457-466.

    Schneider, E. L., S. C. Tucker, and P. S. Williamson. 2003. Floral development in the Nymphaeales. International Journal of Plant Sciences 164(Supplement 5): S279-S292.

    Schneider, H. E., E. Schueltpelz, K. M. Pryer, R. Cranfill, S. Magallon, and R. Lupia. 2004. Ferns diversified in the shadows of angiosperms. Nature 428: 553-557.

    Schönenberger, J., A. A. Anderberg, and K. J. Sytsma. 2005. Molecular phylogenetics and patterns of floral evolution in the Ericales. International Journal of Plant Sciences 166(2): 265-288.

    Schönenberger, J. and M. Von Balthazar. 2006. Reproductive structures and phylogenetic framework of the rosids - progress and prospects. Plant Systematics and Evolution 260(2-4): 87-106.

    Schönenberger, J. and E. M. Friis. 2001. Fossil flowers of ericalean affinity from the Late Cretaceous of southern Sweden. American Journal of Botany 88(3): 467-480.

    Schönenberger, J., E. M. Friis, M. L. Mathews, and P. K. Endress. 2001. Cunoniaceae in the Cretaceous of Europe: evidence from fossil flowers. Annals of Botany 88: 423-437.

    Seberg, O., G. Petersen, A. S. Barfod, and J. I. Davis. 2010. Diversity, Phylogeny, and Evolution in the Monocotyledons. Aarhus: Aarhus University Press, 663 pp.

    Sender, L. M., B. Gomez, J. B. Diez, C. Coiffard, C. Martin-Closas, U. Villanueva-Amadoz, and J. Ferrer. 2010. Ploufolia cerciforme gen. et comb. nov.: aquatic angiosperm leaves from the Upper Albian of northeastern Spain. Review of Palaeobotany and Palynology 161(1-2): 77-86.

    Shan, H., N. Zhang, C. Liu, G. Xu, J. Zhang, Z. Chen, and H. Kong. 2007. Patterns of gene duplication and functional diversification during the evolution of the AP1/SQUA subfamily of plant MADS-box genes. Molecular Phylogenetics and Evolution 44(1): 26-41.

    Sharma, B., C. Guo, H. Kong, and E. M. Kramer. 2011. Petal-specific subfunctionalization of an APETALA3 paralog in the Ranunculales and its implications for petal evolution. New Phytologist 191(3): 870-883.

    Sims, H. J., P. S. Herendeen, and P. R. Crane. 1998. New genus of fossil Fagaceae from the Santonian (Late Cretaceous) of central Georgia, USA. International Journal of Plant Sciences 159(2): 391-404.

    Sims, H. J., P. S. Herendeen, R. Lupia, R. A. Christopher, and P. R. Crane. 1999. Fossil flowers with Normapolles pollen from the Late Cretaceous of southeastern North America. Review of Palaeobotany and Palynology 106(3-4): 131-151.

    Smith, A. C. 1981. Degeneriaceae Pp. 7-13 In: A. C. Smith, Flora Vitiensis Nova, Volume 2. Lawai: Pacific Tropical Botanical Garden, 810 pp.

    Smith, A. C. 1991. Degeneriaceae Pp. 587-588 In: A. C. Smith, Flora Vitiensis Nova, Volume 5. Lawai: National Tropical Botanical Garden, 626 pp.

    Smith, A. C. and S. P. Darwin. 1988. Family 168. Rubiaceae. Pp. 143-376 In: A. C. Smith, Flora Vitiensis Nova, Volume 4. Lawai: Pacific Tropical Botanical Garden, 377 pp.

    Smith, J. F., A. C. Stevens, E. J. Tepe, and C. Davidson. 2008. Placing the origin of two species-rich genera in the late Cretaceous with later species divergence in the Tertiary: a phylogenetic, biogeographic, and molecular dating analysis of Piper and Peperomia (Piperaceae). Plant Systematics and Evolution 275(1-2): 9-30.

    Smith, Stephen A., J. M. Beaulieu, and M. J. Donoghue. 2010. An uncorrelated relaxed-clock analysis suggests an earlier origin for flowering plants. Proceedings of the National Academy of Sciences 107(13): 5897-5902.

    Smith, S. D., C. Ané, and D. A. Baum. 2008. The role of pollinator shifts in the floral diversification of Iochroma (Solanaceae). Evolution 62(4): 793-806.

    Sokoloff, D. D., M. V. Remizowa, B. G. Briggs, and P. J. Rudall. 2009. Shoot architecture and branching pattern in perennial Hydatellaceae (Nymphaeales). International Journal of Plant Sciences 170(7): 869-884.

    Sokoloff, D. D., M. V. Remizowa, T. D. Macfarlane, and P. J. Rudall. 2008. Classification of the early-divergent angiosperm family Hydatellaceae: one genus instead of two, four new species and sexual dimorphism in dioecious taxa. Taxon 57(1): 179-200.

    Sokoloff, D. D., M. V. Remizowa, S. R. Yadav, and P. J. Rudall. 2010. Development of reproductive structures in the sole Indian species of Hydatellaceae, Trithuria konkanensis, and its morphological differences from Australian taxa. Australian Systematic Botany 23(4): 217-228.

    Soltis, D. E., V. A. Albert, J. Leebens-Mack, J. D. Palmer, R. A. Wing, C. W. dePamphilis, H. Ma, J. E. Carlson, N. Altman, S. Kim, P. K. Wall, A. Zuccolo, and P. S. Soltis. 2008. The Amborella genome: an evolutionary reference for plant biology. Genome Biology 9: 402.

    Soltis, D. E., C. D. Bell, S. Kim, and P. S. Soltis. 2008. Origin and early evolution of angiosperms. Pp. 3-25 In: C. D. Schlichting and T. A. Mousseau (eds.), Annals of the New York Academy of Sciences, Volume 1133 Issue, The Year in Evolutionary Biology 2008. New York: The New York Academy of Sciences, 203 pp.

    Soltis, D. E., A. S. Chanderbali, S. Kim, M. Buzgo, and P. S. Soltis. 2007. The ABC model and its applicability to basal angiosperms. Annals of Botany 100(2): 155-163.

    Soltis, D. E., M. Fishbein, R. K. Kuzoff. 2003. Reevaluating the evolution of epigyny: data from phylogenetics and floral ontogeny. International Journal of Plant Sciences 164(5 Supplement): S251-S264.

    Soltis, D. E., H. Ma, M. W. Frohlich, P. S. Soltis, V. A. Albert, D. G. Oppenheimer, N. S. Altman, C. dePamphilis, and J. Leebens-Mack. 2007. The floral genome: an evolutionary history of gene duplication and shifting patterns of gene expression. Trends in Plant Science 12(8): 358-367.

    Soltis, D. E., M. J. Moore, J. G. Burleigh, C. D. Bell, and P. S. Soltis. 2010. Assembling the angiosperm tree of life: progress and future prospects. Annals of the Missouri Botanical Garden 97(4): 514-526.

    Soltis, D. E., A. E. Senters, M. J. Zanis, S. Kim, J. D. Thompson, P. S. Soltis, L. P. Ronse De Craene, P. K. Endress, and J. S. Farris. 2003. Gunnerales are sister to other core eudicots: implications for the evolution of pentamery. American Journal of Botany 90(3): 461-470.

    Soltis, D. E., S. A. Smith, N. Cellinese, K. J. Wurdack, D. C. Tank, S. F. Brockington, N. F. Refulio-Rodriguez, J. B. Walker, M. J. Moore, B. S. Carlsward, C. D. Bell, M. Latvis, S. Crawley, C. Black, D. Diouf, Z. Xi., C. A. Rushworth, M. A. Gitzendanner, K. J. Sytsma, Y.-L. Qiu, K. W. Hilu, C. C. Davis, M. J. Sanderson, R. S. Beaman, R. G. Olmstead, W. S. Judd, M. J. Donoghue, and P. S. Soltis. 2011. Angiosperm phylogeny: 17 genes, 640 taxa. American Journal of Botany 98: 704-730.

    Soltis, D. E. and P. S. Soltis. 2003. The role of phylogenetics in comparative genetics. Plant Physiology 132: 1790-1800.

    Soltis, D. E. and P. S. Soltis. 2004. Amborella not a "basal angiosperm"? Not so fast. American Journal of Botany 91: 997-1001.

    Soltis, D. E., P. S. Soltis, P. K. Endress, and M. W. Chase. 2005. Phylogeny and Evolution of Angiosperms. Sunderland: Sinauer, 370 pp.

    Soltis, P. S., S. F. Brockington, M.-J. Yoo, A. Piedrahita, M. Latvis, M. J. Moore, A. S. Chanderbali, and D. E. Soltis. 2009. Floral variation and floral genetics in basal angiosperms. American Journal of Botany 96(1): 110-128.

    Soltis, P. S., D. E. Soltis, S. Kim, A. Chanderball, and M. Buzgo. 2006. Expression of floral regulators in basal angiosperms and the origin and evolution of ABC-function. Pp. 483-506 In: D. E. Soltis, J. H. Leebens-Mack, P. S. Soltis (eds.), Vol. 44, Advances in Botanical Research, Developmental Genetics of the Angiosperm Flower. Amsterdam: Elsevier.

    Soltis, P. S., D. E. Soltis, M. J. Zanis, and S. Kim. 2000. Basal lineages of angiosperms: relationships and implications for floral evolution. International Journal of Plant Sciences 161(Supplement 6): S97-S107.

    Specht, C. D. and M. E. Bartlett. 2009. Flower evolution: the origin and subsequent diversification of the angiosperm flower. Annual Review of Ecology, Evolution, and Systematics 40: 217-243.

    Srivastava, S. K. 2011. The occurrence of the fossil genus Graminidites in the Maastrichtian Scollard Formation, Alberta, Canada, and its palaeoecological and palaeogeographical significance. Botanical Journal of the Linnean Society 167(2): 235-248.

    Srivastava, S. K. and D. R. Braman. 2010. The revised generic diagnosis, specific description, and synonomy of the late Cretaceous Rosannia manika from Alberta, Canada: its phytogeography and affinity with family Lactoridaceae. Review of Palaeobotany and Palynology 159(1-2): 2-13.

    Staedler, Y. M. and P. K. Endress. 2009. Diversity and lability of floral phyllotaxis in the pluricarpellate families of core Laurales (Gomortegaceae, Atherospermataceae, Siparunaceae, Monimiaceae). International Journal of Plant Sciences 170(4): 522-550.

    Staedler, Y. M., P. H. Weston, and P. K. Endress. 2007. Floral phyllotaxis and floral architecture in Calycanthaceae (Laurales). International Journal of Plant Sciences 168(3): 285-306.

    Stefanovič, S., D. W. Rice, and J. D. Palmer. 2004. Long branch attraction, taxon sampling, and the earliest angiosperms. BMC Evolutionary Biology 4: 35.

    Stockey, R. A. 2006. The fossil record of basal monocots. Pp. 91-106 In: J. T. Columbus, E. A. Friar, C. W. Hamilton, J. M. Porter, L. M. Prince, and M. G. Simpson (eds.), Monocots: Comparative Biology and Evolution, Volume 1, Excluding Poales. Pomona: Rancho Santa Ana Botanic Garden.

    Stockey, R. A. and G. W. Rothwell. 1997. The aquatic angiosperm Trapago angulata from the upper Cretaceous (Maastrichtian) St. Mary's River Formation of southern Alberta. International Journal of Plant Sciences 158(1): 83-94.

    Stockey, R. A. and G. W. Rothwell. 2003. Anatomically preserved Williamsonia (Williamsoniaceae): evidence for Bennettitalean reproduction in the Late Cretaceous of western North America. International Journal of Plant Sciences 164(2): 251-262.

    Stockey, R. A. and G. W. Rothwell. 2009. Distinguishing angiophytes from the earliest angiosperms: a Lower Cretaceous (Valanginian-Hauterivian) fruit-like reproductive structure. American Journal of Botany 96(1): 323-335.

    Stockey, R. A., G. W. Rothwell, and K. R. Johnson. 2007. Cobbania corrugata gen. et comb. nov. (Araceae): a floating aquatic monocot from the Upper Cretaceous of western North America. American Journal of Botany 94(4): 609-624.

    Stopes, M. C. and K. Fujii. 1910. Studies on the structure and affinities of Cretaceous plants. Philosophical Transactions of the Royal Society of London. B201: 1-90.

    Strutzenberger, P., G. Brehm, F. Bodner, and K. Fiedler. 2010. Molecular phylogeny of Eois (Lepidoptera, Geometridae): evolution of wing patterns and host plant use in a species rich group of Neotropical moths. Zoologica Scripta 39(6): 603-620.

    Stuessy, T. F. 2004. A transitional-combinational theory for the origin of angiosperms.  Taxon 53(1): 3-16.

    Stuessy, T. F. 2009. Paradigms in biological classification (1707-2007): has anything really changed? Taxon 58(1): 68-76.

    Stuessy, T. F. 2009. Classification should not be constrained solely by branching topology in a cladistic context. Taxon 58(2): 347-348.

    Su, Y. C. F. and R. M. K. Saunders. 2009. Evolutionary divergence times in the Annonaceae: evidence of a late Miocene origin of Pseuduvaria in Sundaland with subsequent diversification in New Guinea. BMC Evolutionary Biology 9: 153.

    Su, Y. C. F., G. J. D. Smith, and R. M. K. Saunders. 2008. Phylogeny of the basal angiosperm genus Pseuduvaria (Annonaceae) inferred from five chloroplast DNA regions, with interpretation of morphological character evolution. Molecular Phylogenetics and Evolution 48(1): 188-206.

    Sun, G. and D. L. Dilcher. 1997. Discovery of the oldest known angiosperm inflorescence in the world from Lower Cretaceous of Jixi, China. Acta Palaeontologica Sinica 36: 135-142.

    Sun, G., D. L. Dilcher, and S.-L. Zheng. 2008. A review of recent advances in the study of early angiosperms from northeastern China. Palaeoworld 17(3-4): 166-171.

    Sun, G., D. L. Dilcher, S.-L. Zheng, and Z. Zhou. 1998. In search of the first flower: a Jurassic Angiosperm, Archaefructus, from northeast China. Science 282(5394): 1692-1695.

    Sun, G., S. Zheng, D. L. Dilcher, Y. Wang, and S. Mei. 2001. Early Angiosperms and Their Associated Plants from Western Liaoning, China. Shanghai: Scientific and Technological Education Publishing House, 227 pp.

    Sun, G., D. L. Dilcher, H. Wang, and Z. Chen. 2011. A eudicot from the early Cretaceous of China. Nature 471: 625-628.

    Sun, X. J., D.-H. Zhang, and J. S. Hou. 1979. Maastrichtian pollen and spore flora of Inner Mongolia. Acta Botanica 21: 285-393 (in Chinese).

    Sun, Y., X. Wen, and H. Huang. 2010. Population genetic differentiation of Schisandra chinensis and Schizandra sphenanthera as revealed by ISSR analysis. Biochemical Systematics and Ecology 38(3): 257-263.

    Surveswaran, S., R. J. Wang, Y. C. F. Su, and R. M. K. Saunders. 2010. Generic delimitation and historical biogeography in the early-divergent 'ambavioid' lineage of Annonaceae: Cananga, Cyathocalyx and Drepananthus. Taxon 59(6): 1721-1734.

    Sytsma, K. J., J. Morawetz, J. Chris Pires, M. Nepokroeff, E. Conti, M. Zjhra, J. C. Hall, and M. W. Chase. 2002. Urticalean rosids: circumscription, rosid ancestry, and phylogenetics based on rbcL, trnL-F, and ndhF sequences. American Journal of Botany 89(9): 1531-1546.

    Takahashi, M., P. R. Crane, and H. Ando. 1999. Esguieria futabensis sp. nov.; a new angiosperm flower from the Upper Cretaceous (Lower Coniacian) of northeastern Honshu, Japan. Paleontological Research 3: 81-87.

    Takahashi, M., P. R. Crane, and H. Ando. 1999. Fossil flowers and associated plant fossils from the Kamikitaba locality (Ashizawa Formation, Futuba Group, Lower Coniacian, Upper Cretaceous) of northeast Japan. Journal of Plant Research 112(2): 187-206.

    Takahashi, M., P. R. Crane, and S. R. Manchester. 2003. Hironoia fusiformis gen. et sp. nov.: a cornalean fruit from the Kamikitaba locality (Upper Cretaceous; Lower Coniacian) in northeastern Japan. Journal of Plant Research 115(6): 463-473.

    Takahashi, M., E. M. Friis, and P. R. Crane. 2007. Fossil seeds of Nymphaeales from the Tamayama Formation (Futaba Group), late Cretaceous (early Santonian) of northeastern Honshu, Japan. International Journal of Plant Sciences 168(3): 341-350.

    Takahashi, M., E. M. Friis, P. S. Herendeen, and P. R. Crane. 2008. Fossil flowers of Fagales from the Kamikitaba locality (early Coniacian, late Cretaceous) of northeastern Japan. International Journal of Plant Sciences 169(7): 899-907.

    Takahashi, M., E. M. Friis, K. Uesugi, Y. Suzuki, and P. R. Crane. 2008. Floral evidence of Annonaceae from the late Cretaceous of Japan. International Journal of Plant Sciences 169(7): 908-917.

    Takahashi, M., P. S. Herendeen, and P. R. Crane. 2001. Lauraceous flowers from the Kamikitaba locality (Lower Coniacian; Upper Cretaceous) of northeast Japan. Journal of Plant Research 114(4): 429-434.

    Takhtajan, A. 1986. Floristic Regions of the World. Berkeley: University of California Press, 522 pp.

    Takhtajan, A. 1997. Diversity and Classification of Flowering Plants. New York: Columbia University Press, 643 pp.

    Takhtajan, A. 2009. Diversity and Classification of Flowering Plants, Second Edition. Berlin: Springer Verlag, 872 pp.

    Tamaki, I., S. Setsuko, and N. Tomaru. 2009. Estimation of outcrossing rates at hierarchical levels of fruits, individuals, populations, and species in Magnolia stellata. Heredity 102: 381-388.

    Taylor, D. W. 2008. Phylogenetic analysis of Cabombaceae and Nymphaeaceae based on vegetative and leaf architectural characters. Taxon 57(4): 1082-1095.

    Taylor, D. W., G. J. Brenner, and S. H. Basha. 2008. Scutifolium jordanicum gen. et sp. nov. (Cabombaceae), an aquatic fossil plant from the lower Cretaceous of Jordan, and the relationships of related leaf fossils to living genera. American Journal of Botany 95(3): 340-352.

    Taylor, D. W., D. L. Dilcher, and S. Hu. 2010. Coevolution of early angiosperms and their pollinators: evidence from pollen. Palaeontographica Abt. B 283: 103-135.

    Taylor, E. L. and T. N. Taylor. 2009. Seed ferns from the late Paleozoic and Mesozoic: any angiosperm ancestors lurking there? American Journal of Botany 96(1): 237-251.

    Taylor, M. L., B. L. Gutman, N. A. Melrose, A. M. Ingraham, J. A. Schwartz, and J. M. Osborn. 2008. Pollen and anther ontogeny in Cabomba caroliniana (Cabombaceae, Nymphaeales). American Journal of Botany 95(4): 399-413.

    Taylor, M. L., T. D. Macfarlane, and J. H. Williams. 2010. Reproductive ecology of the basal angiosperm Trithuria submersa (Hydatellaceae). Annals of Botany 106(6): 909-920.

    Taylor, M. L. and J. H. Williams. 2009. Consequences of pollination syndrome evolution for postpollination biology in an ancient angiosperm family. International Journal of Plant Sciences 170(5): 584-598.

    Taylor, T. N., E. L. Taylor, and M. Krings. 2009. Paleobotany: The Biology and Evolution of Fossil Plants, Second Edition. Burlington: Elsevier Academic Press, 1230 pp.

    Tejada, M. L. G., K. Suzuki, J. Kuroda, R. Coccioni, J. J. Mahoney, N. Ohkouchi, T. Sakamoto, and Y. Tatsumi. 2009. Ontong Java Plateau eruption as a trigger for the early Aptian oceanic anoxic event. Geology 37(9): 855-858.

    Teichert, H., S. Döttert, and G. Gottsberger. 2011. Heterodichogamy and nitidulid beetle pollination in Anaxagorea prinoides, an early divergent Annonaceae. Plant Systematics and Evolution 291(1-2): 25-33.

    Tidwell, W. D., S. R. Rushforth, J. L. Reveal, and H. Behunin. 1970. Palmoxylon simperi and Palmoxylon pristina: two pre-Cretaceous angiosperms from Utah. Science 168: 835-840.

    Thien, L. B., H. Azuma, and S. Kawano. 2000. New perspectives on the pollination biology of basal angiosperms. International Journal of Plant Sciences 161(Supplement 6): S225-S235.

    Thien, L. B., P. Bernhardt, M. S. Devall, Z. Chen, Y. Luo, J.-H. Fan, L.-C. Yuan, and J. H. Williams. 2009. Pollination biology of basal angiosperms (ANITA grade). American Journal of Botany 96(1): 166-182.

    Thien, L. B., T. L. Sage, T. Jaffré, P. Bernhardt, V. Pontieri, P. H. Weston, D. Malloch, H. Azuma, S. W. Graham, M. A. McPherson, H. S. Rai, R. F. Sage, and J.-L. Dupre. 2003. The population structure and floral biology of Amborella trichopoda (Amborellaceae). Annals of the Missouri Botanical Garden 90(3): 466-490.

    Theißen, G. and A. Becker. 2004. Gymnosperm orthologues of class B floral homeotic genes and their impact on understanding flower origin. Critical Reviews in Plant Sciences 23(2): 129-148.

    Theißen, G. and R. Melzer. 2007. Molecular mechanisms underlying origin and diversification of the angiosperm flower. Annals of Botany 100(3): 1-17.

    Thorne, J. L. and H. Kishino. 2002. Divergence time and evolutionary rate estimation with multilocus data. Systematic Biology 51: 689-702.

    Thorne, R. F. 1968. Synopsis of a putatively phylogenetic classification of the flowering plants. Aliso 6: 57-66.

    Thorne, R. F. 1992. Classification and geography of the flowering plants. The Botanical Review 58: 225-348.

    Thorne, R. F. and J. L. Reveal. 1992. An updated classification of the class Magnoliophyta ('Angiospermae'). The Botanical Review 73: 67-181.

    Tobe, H., T. Jaffré, and P. H. Raven. 2000. Embryology of Amborella (Amborellaceae): descriptions and polarity of character states. Journal of Plant Research 113(3): 271-280.

    Tobe, H., Y. Kimoto, and N. Prakash. 2007. Development and structure of the female gametophyte in Austrobaileya scandens (Austrobaileyaceae). Journal of Plant Research 120(3): 431-436.

    Tomlinson, P. B. and A. C. Smith. 1970. Joinvilleaceae, a new family of monocotyledons. Taxon 19: 887-889.

    Tschan, G. F., T. Denk, and M. von Balthazar. 2008. Credneria and Platanus (Platanaceae) from the late Cretaceous (Santonian) of Quedlinburg, Germany. Review of Palaeobotany and Palynology 152(3-4): 211-236.

    Uhl, N. W. and J. Dransfield. 1987. Genera Palmarum, A Classification of Palms Based on the Work of Harold E. Moore, Jr. Lawrence: Allen Press, 610 pp.

    Upchurch, G. R. and D. L. Dilcher. 1990. Cenomanian Angiosperm Leaf Megafossils, Dakota Formation, Rose Creek Locality, Jefferson County, Southeastern Nebraska. U.S. Geological Survey Bulletin 1915.

    Upchurch, G. R. and J. A. Wolfe. 1987. Mid-Cretaceous to early Tertiary vegetation and climate: evidence from fossil leaves and woods. Pp. 75-105 In: E. M. Friis, W. G. Chaloner, and P. R. Crane (eds.), The Origin of Angiosperms and Their Biological Consequences. Cambridge: Cambridge University Press, 358 pp.

    Vamosi, J. C. and S. M. Vamosi. 2010. Key innovations within a geographical context in flowering plants: towards resolving Darwin's abominable mystery. Ecology Letters 13(10): 1270-1279.

    Verma, J. K. 1958. On an inflorescence of a new petrified monocot flower, Shuklanthus superbum gen. et sp. nov. from the Deccan Intertrappean series of Madhya Pradesh State, central India. Journal of the Palaeontological Society of India 3: 185-200.

    Vermeij, G. J. 2011. The energetics of modernization: the last one hundred million years of biotic evolution. Paleontological Research 15(2): 54-61.

    Viaene, T., D. Vekemans, V. F. Irish, A. Geeraerts, S. Huysmans, S. Janssens, E. Smets, and K. Geuten. 2009. PISTILLATA - duplications as a mode for floral diversification in (basal) asterids. Molecular Biology and Evolution 26(11): 2627-2645.

    Vialette-Guiraud, A. C. M., M. Alaux, F. Legeai, C. Finet, P. Chambrier, S. C. Brown, A. Chauvet, C. Magdalena, P. J. Rudall, and C. P. Scutt. 2011. Cabomba as a model for studies of early angiosperm evolution. Annals of Botany 108(4): 589-598.

    Vidal-Russell, R. and D. L. Nickrent. 2008. The first mistletoes: origins of aerial parasitism in Santalales. Molecular Phylogenetics and Evolution 47(2): 523-537.

    Viehofen, A., C. Hartkopf-Fröder, and E. M. Friis. 2008. Inflorescences and flowers of Mauldinia angustiloba sp. nov. (Lauraceae) from middle Cretaceous karst infillings in the Rhenish Massif, Germany. International Journal of Plant Sciences 169(7): 871-889.

    Vogel, S. and F. Hadacek. 2004. Contributions to the functional anatomy and biology of Nelumbo nucifera (Nelumbonaceae) III. An ecological reappraisal of floral organs. Plant Systematics and Evolution 249(3-4): 173-189.

    Volkova, P. A. and A. B. Shipunov. 2008. Morphological variation of Nymphaea (Nymphaeaceae) in European Russia. Nordic Journal of Botany 25(5-6): 329-338.

    Wang, H., M. J. Moore, P. S. Soltis, C. D. Bell, S. F. Brockington, R. Alexandre, C. C. Davis, M. Latvis, S. R. Manchester, and D. E. Soltis. 2009. Rosid radiation and the rapid rise of angiosperm-dominated forests. Proceedings of the National Academy of Sciences 106(10): 3853-3858.

    Wang, H. and D. L. Dilcher. 2006. Aquatic angiosperms from the Dakota Formation (Albian, Lower Cretaceous), Hoisington III Locality, Kansas, U.S.A. International Journal Plant Sciences 167(2): 385-401.

    Wang, H., D. L. Dilcher, R. N. Schwarzwalder, and J. Kvaček. 2011. Vegetative and reproductive morphology of an extinct early Cretaceous member of the Platanaceae from the Braun's Ranch Locality, Kansas, U.S.A. International Journal Plant Sciences 172(1): 139-157.

    Wang, W., A.-M. Lu, Y. Ren, M. E. Endress, and Z.-D. Chen. 2009. Phylogeny and classification of Ranunculales: evidence from four molecular loci and morphological data. Perspectives in Plant Ecology, Evolution, and Systematics 11(2): 81-110.

    Wang, X. 2008. Mesofossils with platanaceous affinity from the Dakota Formation (Cretaceous) in Kansas, USA. Palaeoworld 17(3-4): 246-252.

    Wang, X., S. Duan, B. Geng, J. Cui, and Y. Yang. 2007. Schmeissneria: A missing link to angiosperms? BMC Evolutionary Biology 7: 14-26.

    Wang, X. and S-L. Zheng. 2009. The earliest normal flower from Liaoning Province, China. Journal of Integrative Plant Biology 51(8): 800-811.

    Wang, Y.-H., D. K. Ferguson, G.-P. Feng, Y.-F. Wang, S. G. Zhilin, C.-S. Li, P.-T. Svetlana, J. Yang, and A. G. Ablaev. 2009. The phytogeography of the extinct angiosperm Nordenskioldia (Trochodendraceae) and its response to climate changes. Palaeogeography, Palaeoclimatology, and Palaeoecology 280(1-2): 183-192.

    Wang, Z.-H., J. Li, J. G. Conran, and H.-W. Li. 2010. Phylogeny of the southeast Asian genus Neocinnamomum H. Liu (Lauraceae). Plant Systematics and Evolution 290(1-4): 173-184.

    Wanke, S., M. A. Jaramillo, T. Borsch, M.-S. Samain, D. Quandt, and C. Neinhus. 2007. Evolution of Piperales: matK gene and trnK intron sequence data reveal lineage specific resolution contrast. Molecular Phylogenetics and Evolution 42: 477-497.

    Wanntorp, L., V. Vajda, and J. I. Raine. 2011. Past diversity of Proteaceae on subantarctic Campbell Island, a remote outpost of Gondwana. Cretaceous Research 32(3): 357-367.

    Wappler, T., E. D. Currano, P. Wilf, J. Rust, and C. C. Labandeira. 2009. No post-Cretaceous ecosystem depression in European forests? Rich insect-feeding damage on diverse middle Palaeocene plants, Menat, France. Proceedings of the Royal Society of London, Series B, Biological Sciences 276(1677): 4271-4277.

    Warner, K. A., P. J. Rudall, and M. W. Frohlich. 2009. Environmental control of sepalness and petalness in perianth organs of waterlilies: a new Mosaic Theory for the evolutionary origin of a differentiated perianth. Journal of Experimental Botany 60(12): 3559-3574.

    Watanabe, K., T. Ohi-Toma, and J. Murata. 2008. Multiple hybridization in the Aristolochia kaempferi group (Aristolochiaceae): evidence from reproductive isolation and molecular phylogeny. American Journal of Botany 95(7): 885-896.

    Weaver, L., S. McLoughlin, and A. N. Drinnan. 1997. Fossil woods from the Upper Permian Bainmedart Coal Measures, northern Prince Charles Mountains, east Antarctica. Journal of Australian Geology and Geophysics 16: 655-676.

    Weerasooriya, A. D. and R. M. K. Saunders. 2010. Monograph of Mitrephora (Annonaceae). Systematic Botany Monographs 90: 1-167.

    Wheeler, E. A. and T. M. Lehman. 2000. Late Cretaceous woody dicots from the Aguja and Javelina formations, Big Bend National Park, Texas, USA. IAWA Journal 21(1): 83-120.

    Wheeler, E. A., T. M. Lehman, and P. Gasson. Javelinoxylon, a new genus of malvalean tree from the Upper Cretaceous of Big Bend National Park, Texas. American Journal of Botany 81(6): 703-710.

    Wheeler, E. A., J. McClammer, and C. A. LaPasha. 1995. Similarities and differences in dicotyledonous woods of the Cretaceous and Paleocene of the San Juan Basin, New Mexico, USA. IAWA Journal 16: 223-254.

    Whipple, C. J., M. J. Zanis, E. A. Kellogg, and R. J. Schmidt. 2007. Conservation of B class gene expression in the second whorl of a basal grass and outgroups links the origin of lodicules and petals. Proceedings of the National Academy of Sciences 104(3): 1081-1086.

    Wikström, N., V. Savolainen, and M. W. Chase. 2001. Evolution of the angiosperms: calibrating the family tree. Proceedings of the Royal Society of London, Series B, Biological Sciences 268(1482): 2211-2220.

    Wilf, P., C. C. Labandeira, W. J. Kress, C. L. Staines, D. M. Windsor, A. L. Allen, and K. R. Johnson. 2000. Timing the radiations of leaf beetles: hispines on gingers from latest Cretaceous to Recent. Science 289: 291-294.

    Williams, J. H. 2009. Amborella trichopoda (Amborellaceae) and the evolutionary developmental origins of the angiosperm progamic phase. American Journal of Botany 96(1): 166-182.

    Williams, J. H., R. T. McNeilage, M. T. Lettre, and M. L. Taylor. 2010. Pollen tube growth and the pollen tube pathway of Nymphaea odorata (Nymphaeaceae). Botanical Journal of the Linnaean Society 162(4): 581-593.

    Williams, J. H. and W. E. Friedman. 2004. The four-celled female gametophyte of Illicium (Illiciaceae; Austrobaileyales): Implications for understanding the origin and early evolution of monocots, eumagnoliids, and eudicots. American Journal of Botany 91(3): 332-351.

    Williams, J. H. and K. S. Kennard. 2006. Microsatellite loci for the basal angiosperm Austrobaileya scandens (Austrobaileyaceae). Molecular Ecology Notes 6(1): 201-203.

    Wilson, P., A. D. Wolfe, W. S. Armbruster, and J. D. Thomson. 2007. Constrained lability in floral evolution: counting convergent origins of hummingbird pollination in Penstemon and Keckiella. New Phytologist 176: 883-890.

    Wing, S. L. and L. D. Boucher. 1998. Ecological aspects of the Cretaceous flowering plant radiation. Annual Review of Earth and Planetary Sciences 26: 379-421.

    Wing, S. L., F. Herrera, C. A. Jaramillo, C. Gómez-Navarro, P. Wilf, and C. C. Labandeira. 2009. Late Paleocene fossils from the Cerrejón Formation, Columbia, are the earliest record of Neotropical rainforest. Proceedings of the National Academy of Sciences 106(44): 18843-18848.

    Winkler, I. S., C. C. Labandeira, T. Wappler, and P. Wilf. 2010. Distinguishing Agromyzidae (Diptera) leaf mines in the fossil record: new taxa from the Palaeogene of North America and Germany and their evolutionary implications. Journal of Paleontology 84(5): 935-954.

    Winkler, I. S., C. Mitter, and S. J. Scheffer. 2009. Repeated climate-linked host shifts have promoted diversification in a temperate clade of leaf-mining flies. Proceedings of the National Academy of Sciences 106(43): 18103-18108.

    Wojciechowski, M. F., M. Lavin, and M. J. Sanderson. 2004. A phylogeny of legumes (Leguminosae) based on analysis of the plastid matK gene resolves many well-supported subclades within the family. American Journal of Botany 91(11): 1846-1862.

    Wolfe, J. A. and G. R. Upchurch, Jr. 1987. North American nonmarine climates and vegetation during the late Cretaceous. Palaeogeography, Palaeoclimatology, Palaeoecology 61: 33-77.

    Worberg, A., D. Quandt, A-M. Barniske, C. Löhne, K. W. Hilu, and T. Borsch. 2007. Phylogeny of basal eudicots: insights from non-coding and rapidly evolving DNA. Organisms Diversity and Evolution 7(1): 55-77.

    Yamada, T., R. Imaichi, N. Prakash, and M. Kato. 2003. Developmental morphology of ovules and seeds of Austrobaileyales. Australian Journal of Botany 51(5): 555-564.

    Yamada, T., M. Ito, and M. Kato. 2003. Expression pattern of INNER NO OUTER homologue in Nymphaea (water lily family, Nymphaeaceae). Developmental Genes and Evolution 213: 510-513.

    Yamada, T., M. Ito, and M. Kato. 2004. YABBY2-homologue expression in lateral organs of Amborella trichopoda (Amborellaceae). International Journal of Plant Sciences 165(6): 917-924.

    Yamada, T., H. Nishida, M. Umebayashi, K. Uemura, and M. Kato. 2008. Oldest record of Trimeniaceae from the early Cretaceous of northern Japan. BMC Evolutionary Biology 8:135.

    Yamada, T., H. Tobe, R. Imaichi, and M. Kato. 2001. Developmental morphology of ovules of Amborella trichopoda (Amborellaceae) and Chloranthus serratus (Chloranthaceae). Botanical Journal of the Linnaean Society 137(3): 277-290.

    Yellina, A. L., S. Orashakova, S. Lange, R. Erdmann, J. Leebens-Mack, and A. Becker. 2010. Floral homeotic C function genes repress specific B function genes in the carpel whorl of the basal eudicot California poppy (Eschscholzia californica). EvoDevo 1(1): 13.

    Yin, C., U. Richter, T. Börner, and A. Weihe. 2010. Evolution of plant phage-type RNA polymerases: the genome of the basal angiosperm Nuphar advena encodes two mitochondrial and one plastid phage-type RNA polymerases. BMC Evolutionary Biology 10: 379.

    Yoo, M.-J., C. D. Bell. P. S. Soltis, and D. E. Soltis. 2005. Divergence times and historical biogeography of Nymphaeales. Systematic Botany 30(4): 693-704.

    Xiang, Q.-Y. (Jenny), D. T. Thomas, and Q. Ping. 2011. Resolving and dating the phylogeny of Cornales - effects of taxon sampling, data partitions, and fossil calibrations. Molecular Phylogenetics and Evolution 59(1): 123-138.

    Xu, F. and L. Ronse de Craene. 2010. Floral ontogeny of Annonaceae: evidence for high variability in floral form. Annals of Botany 106(4): 591-605.

    Xu, F. and L. Ronse de Craene. 2010. Floral ontogeny of Knema and Horsefieldia (Myristicaceae): evidence for a complex androecial evolution. Botanical Journal of the Linnaean Society 164(1): 42-52.

    Xu, F. and P. J. Rudall. 2006. Comparative floral anatomy and ontogeny in Magnoliaceae. Plant Systematics and Evolution 258(1-2): 1-15.

    Zahn, L. M., H. Kong, J. H. Leebens-Mack, S. Kim, P. S. Soltis, L. L. Landherr, D. E. Soltis, C. W. dePamphilis, and H. Ma. 2005. The evolution of the SEPALLATA subfamily of MADS-Box genes: a preangiosperm origin with multiple duplications throughout angiosperm history. Genetics 169: 2209-2223.

    Zanis, M. J., P. S. Soltis, Y.-L. Qiu, E. Zimmer, and D. E. Soltis. 2003. Phylogenetic analyses and perianth evolution in basal angiosperms. Annals of the Missouri Botanical Garden 90: 129-150.

    Zavada, M. S. 2007. The identification of fossil angiosperm pollen and its bearing on the time and place of the origin of angiosperms. Plant Systematics and Evolution 263: 117-134.

    Zavada, M. S. and J. M. Benson. 1987. First fossil evidence for the primitive angiosperm family Lactoridaceae. American Journal of Botany 74(10): 1590-1594.

    Zhang, L.-B., M. P. Simmons, A. Kocyan, and S. S. Renner. 2006. Phylogeny of the Cucurbitales based on DNA sequences of nine loci from three genomes: implications for morphological and sexual system evolution. Molecular Phylogenetics and Evolution 39(2): 305-322.

    Zhang, S.-D., D. E. Soltis, Y. Yang, D.-Z. Li, and T.-S. Yi. 2011. Multi-gene analysis provides a well-supported phylogeny of Rosales. Molecular Phylogenetics and Evolution 60(1): 21-28.

    Zhang, X.-M., J. Wen, Z. L. Dao, T. J. Motley, and C. L. Long. 2010. Genetic variation and conservation assessment of Chinese populations of Magnolia cathcartii (Magnoliaceae), a rare evergreen tree from the south-central China hotspot in the eastern Himalayas. Journal of Plant Research 123(3): 321-331.

    Zhou, L., Y. C. F. Su, P. Chalermglin, and R. M. K. Saunders. 2010. Molecular phylogenetics of Uvaria (Annonaceae): relationships with Balonga, Dasoclema, and Australian species of Melodorum. Botanical Journal of the Linnaean Society 163(1): 33-43.

    Zhou, Q. and D. Fu. 2008. Reproductive morphology of Nuphar (Nymphaeaceae), a member of basal angiosperms. Plant Systematics and Evolution 272(1-4): 79-96.

    Zhu, X.-Y., M. W. Chase, Y.-L. Qiu, H.-Z. Kong, D. L. Dilcher, J.-H. Li, and Z.-D. Chen. 2007. Mitochondrial matR sequences help to resolve deep phylogenetic relationships in rosids. BMC Evolutionary Biology 7: 217.

    Zuccolo, A., J. E. Bowers, J. C. Estill, Z. Xiong, M. Luo, A. Sebastian, J. L. Goicoechea, K. Collura, Y. Yu, A. Chanderbali, D. E. Soltis, S. Chamala, B. Barbazuk, P. S. Soltis, V. A. Albert, H. Ma, D. Mandoli, J. Banks, J. E. Carlson, J. Tompkins, C. W. dePamphilis, R. A. Wing, and J. Leebens-Mack. 2011. A physical map for the Amborella trichopoda genome sheds light on the evolution of angiosperm genome structure. Genome Biology 12: R48.

    [ top ]



    ESSAY CONTENTS

  • Angiosperm Classification
  • Angiosperm Ghost Lineage
  • Basal Angiosperms
  • Commelinid Monocots
  • Conclusions on the Evolution of Mesozoic Angiosperms
  • Core Eudicots, Rosids, and Asterids
  • Cretaceous Explosive Radiation of Angiosperms
  • Crown Group Flowering Plants
  • Eudicots
  • Fossil History
  • Literature Cited on the Evolution of Mesozoic Angiosperms
  • Monocots
  • Stem Group Flowering Plants

  • [ top ]

    NOVEMBER 11, 2011


    INTERNET SERVICES
    by
    runadun.net