[ Essays on the Origin of Angiosperms ]
Molecular coevolution of insect and seed plant developmental tool kits and cis-regulatory modules (CRMs) might explain diversification in Paleozoic seed plant lineages, origin of the flower, and the origin of angiosperms and coevolution with early holometabolous insects.
Were insect and shrub coevolutionary compartments of the late Paleozoic hypoxic icehouse and later hot house, venues of the first angiosperms? ... ORIGIN OF ANGIOSPERMS
Pteridosperms might not constitute the "backbone of seed-plant phylogeny," but instead the "lineage" could suffer from spinal bifida.
Further, there is little or no support in the fast-moving literature on tool kits for past proposals on the evo-devo of bitegmic angiosperm ovules from axillary reproductive organs of Mesozoic Caytoniales (see Mathews & Kramer Tansley Review). Simply put, Caytonia probably had nothing to do with the origin of angiosperms ... PALEOBOTANY OF ANGIOSPERM ORIGINS
Do crown group flowering plants represent a loose amalgam of parallel evolutionary lines traceable to surviving early Triassic remnants of already divergent stem group angiosperms? ... EVOLUTION OF MESOZOIC ANGIOSPERMS
[ Library and Student Resources ]
This sample reading list of books and book chapters is intended for persons with advanced college level biology training who have an interest in current research on the origin of flowering plants ... KEY TO THE LITERATURE
Each year I will select a scientific paper, book chapter, or book as being of paramount importance toward finding a solution to the enigmatic origin of angiosperms ... PAPER OF THE YEAR
Need a sample data set for your course in phylogenetics? Advanced students may practice with gigantopteroid data ... SEED PLANT DATA SET AND MATRIXES
[ Paleozoic Gigantopteroids and Vojnovskyales ]
Vojnovskyales and gigantopteroids are poorly understood Carboniferous and Permian gymnosperms with possible evolutionary ties to the angiosperms.
Potential importance of gigantopteroid and vojnovskyalean seed plant fossils in deciphering the ancestry of flowering plants and paraphyletic clades of gymnosperms reflects my choice of the unusual title for this web site.
Are Delnortea abbottiae and Evolsonia texana gigantopteroids or gigantopterids? Clearly, detailed studies of permineralized material of fertile gigantopteroid leaves, when unearthed, thin-sectioned, and described, would shed light on these enigmatic forms and help us to decipher their evolutionary relationships with sympatric Paleozoic congeners ... GIGANTOPTEROIDS
Vojnovskyaleans were late Paleozoic seed plants with both long- and short- (spur) shoots. The bisexual cone axes and monocot-like foliage resembled the enigmatic Triassic fossil seed plant Sanmiguelia lewisii ... VOJNOVSKYALES
[ Statement on Evolution ]
The gigantopteroid web site owner and writer, peer reviewers, and contributors adopt the Botanical Society of America's policy on evolution ... BOTANICAL SOCIETY OF AMERICA
Over millions of years of Paleozoic time as global atmospheric oxygen level (pO2) fluctuated, certain chewing, crawling, ovipositioning, piercing, siphoning, sponging, stinging and sucking insects probably became obligate residents of host seed plant shrubs and trees.
Air pockets at the base of sheathing leathery leaves and around developing stems and organs, and reproductive modules of monopodial Carboniferous seed plants might have provided phytophagous insects with oxygen gas, food, and shelter from predators, cold, and ultraviolet radiation.
Phytophagous insect associates of developmentally plastic Permian seed plant shrubs survived the end-Permian extinction. Acidification of substrates, hypoxia, increases in ambient temperature, and "trigger and kill" events adversely affected both insects and tetrapods in a hot-house world ... PALEOECOLOGY OF GLOBAL CATASTROPHE
Were Paleozoic changes in atmospheric pO2 the selective force driving the molecular evolution of gas-binding hemocyanin respiratory enzymes and moulting storage proteins of early arthropods? ... INSECT HEXAMERINS
Are the helix-turn-helix (HTH) DNA-binding motifs of seed plant Leafy enzyme and the insect homeodomain protein Engraled, products of molecular coevolution? ... LFY ENZYME STRUCTURE
One key ingredient left out of the steaming cauldron of past ideas on the origin of flowering plants is a class of mobile chromosome parasites known as transposable elements (TEs) ... LTR RETROTRANSPOSONS
What did external biotic and physical factors have to do with the evo-devo of larval moult cycles and innovative mouthparts of phytophagous insects? ... ORIGIN OF THE HOLOMETABOLA
Consideration of both small gene duplications and whole genome duplications (WGDs) is important in understanding the timing of the origin of angiosperms and radiation of basal flowering plants and eudicots ... GENE DUPLICATIONS
Were secretions of insect eggs, instars, larvae, pupae, and adults, when applied to shoot apical meristems (SAMs) with mechanical force, a source of signals that affected plant growth and development at the genetic level in nuclei of host cells of certain monopodial Permo-Triassic seed plants? ... SIGNALS
Implications of cross-Kingdom horizontal transfer of bits and pieces of tool kit DNA from accumulating transposons originating in fungal and/or insect bodies to genomes of seed plant hosts are understandably profound ... COEVOLUTION
There is growing consensus among molecular systematists and some paleobotanists on the existence of a 160 million year old angiosperm ghost lineage beginning with
divergence's) of flowering plants from the MRCA prior to the end-Permian extinction ... ANGIOSPERM GHOST LINEAGE
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 of ovule-bearing Phasmatocycas bridwellii leaves to form carpels, ovaries, and pistils ... HYPOTHETICAL PALEOZOIC PROTOFLOWERS
[ Biostratigraphy of the Permian Standard Section ]
Uplifted and tilted beds in the Del Norte and Glass Mountains of southwestern North America consist of massive Permian marine and transitional, deltaic, sedimentary rock exposures.
Rocks in these mountain ranges yield fossilized coral reefs with brachiopods, conodonts, graptolites, and sponges, and deltaic transitional layers with preserved freshwater snails, walchian conifers, and gigantopteroid seed plants ... ARTICLE