Plants in Mesozoic Time
Morphological Innovations, Phylogeny, Ecosystems
Publication Year: 2010
Published by: Indiana University Press
Preface, Dedication, and Acknowledgements
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The Mesozoic was a curious time. On the surface, it resembled today’s world, but instead of large herbivores like elephants, there were sauropods; instead of large carnivores like lions, there were tyrannosaurs; instead of trees with flowers and broad leaves, there were pteridosperms and bennettitaleans with naked seeds and fernlike fronds. The Mesozoic was thus a wondrous time. It was an era of...
The Career of Ted Delevoryas: Appreciation and Publications
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It is impossible to define a career in an introduction to a book, especially one as distinguished as the career of Ted Delevoryas. Any feat of this magnitude would have the writer begging for more space, adding additional superlatives to the prose, and always questioning whether the appropriate tenor has been achieved or...
Part 1: Morphological Innovations in Mesozoic Plants
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1. Architectural Innovation and Developmental Controls in Some Mesozoic Gymnosperms, or, Why Do The Leaf Crowns in Mesozoic Forests Look Tufted?
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The concept of plant architecture was first formalized by Hall�, Oldeman, and Tomlinson in 1978 and was based on patterns observed in forestforming trees. Plant architecture is dependent primarily on the function of meristems and the growth patterns of shoots and roots. There has been an evolutionary progression in architecture...
2. Modern Traits in Early Mesozoic Sphenophytes: The Equisetum-like Cones of Spaciinodum collinsonii with In Situ Spores and Elaters from the Middle Triassic of Antarctica
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Structurally preserved cones of the early Middle Triassic sphenophyte Spaciinodum collinsonii have been discovered within permineralized peat from Fremouw Peak, Antarctica. Cones consist of whorls of peltate sporangiophores bearing approximately 10 sporangia each. Spores have a perispore and four elaters with spatulate ends, making Spaciinodum the earliest known Triassic sphenophyte...
3. Pollen and Coprolite Structure in Cycadeoidea (Bennettitales): Implications for Understanding Pollination and Mating Systems in Mesozoic Cycadeoids
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The Mesozoic seed plant group Bennettitales is most comprehensively known from permineralized fossils of Cycadeoidea from the Early Cretaceous of North America. Cones were bisporangiate and have been interpreted as remaining closed at maturity. Consequently, self-pollination has been hypothesized in Cycadeoidea through...
4. Independent Evolution of Seed Enclosure in the Bennettitales: Evidence from the Anatomically Preserved Cone Foxeoidea connatum gen. et sp. nov.
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A new anatomically preserved ovulate cone from the Lower Cretaceous of western Canada reveals an independent evolution of ovule enclosure in the Bennettitales. Foxeoidea connatum gen. et sp. nov. consists of an ovulate receptacle bearing tightly packed and highly fused seeds and interseminal scales. The cone axis has a eustele from which collateral bundles diverge to vascularize individual...
5. A Mosaic of Characters in a New Whole-Plant Araucaria, A. delevoryasii Gee sp. nov., from the Late Jurassic Morrison Formation of Wyoming, U.S.A.
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A new fossil flora consisting of many hundreds of specimens was recovered from the Late Jurassic Morrison Formation (Brushy Basin Member) from a new quarry, the Howe-Stephens Quarry, on the Howe Ranch in north-central Wyoming. These coalified plant compressions occur alongside the remains of a diverse dinosaur fauna and represent the plant parts (woody shoots with leaves...
6. Major Innovations in Angiosperm Evolution
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Both the evolution of flowering plants and the evolution of flowers involved many innovations which extended over 75 million years. These innovations are presented here in six steps and center upon the reproductive biology of the flowering plants, often involving coevolution with animals to increase the potential for outcrossing. These innovations are as follows: (1) positioning of pollen and seed...
7. Implications of Fossil Floral Data on Understanding the Early Evolution of Molecular Developmental Controls of Flowers
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A review of Early Cretaceous angiosperm flowers shows that all groups of reproductive developmental control genes were present, but that variation in some characteristics indicates some were not as canalized as they are now in living angiosperms. For example, many reproductive organ characters were uniform, whereas flower and inflorescence structures ...
Part 2: Phylogeny of Mesozoic Plants
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8. Late Triassic Ginkgoleans of North America
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Ginkgoaleans of Late Triassic age are uncommon in North America and are known from only three widely separated parts of the continent. The productive areas are situated along the mid-Atlantic seaboard, in the Arctic Archipelago of Canada, and in the southwestern United States and adjacent parts of northwestern Mexico...
9. Review of the Cycads and Bennettitaleans from the Mesozoic of Argentina
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Cycads and bennettitaleans from Argentina are thoroughly reviewed in light of their fossil record and recent findings from a geographic and stratigraphic perspective. The history of these groups is traced from their first appearance in the Triassic to the last record of cycads in the early Paleogene. Selected cycadophyte...
10. The Bennettitales (Cycadeoidales): A Preliminary Perspective on This Arguably Enigmatic Group
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Most phylogenetic analyses of morphological and structural characters have placed the Bennettitales comfortably within an anthophyte clade that includes angiosperms and the Gnetales. The Bennettitales–Gnetales relationship has come into question because nucleic acid sequence–based phylogenies place the Gnetales with other gymnosperms outside of the anthophyte clade. Yet recent...
11. Endemism of Early Cretaceous Conifers in Western Gondwana
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Early Cretaceous conifers occur in many parts of Western Gondwana. The families represented are the Araucariaceae, Cheirolepidiaceae, Podocarpaceae, and the taxodiaceous Cupressaceae. On the genus level, many taxa have a global distribution; however, some of them are restricted to the southern regions. In regard to species level, a great number of endemics are located in southwestern...
12. Oldest Known Dicotyledonous Lianas from the Early Late Cretaceous of Utah and New Mexico, U.S.A.
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The remains of more than 15 specimens of the oldest known fossil lianous dicotyledonous stems have been discovered embedded in the false trunks of four species of the tree fern Tempskya Corda in mainly early Late Cretaceous (Cenomanian) strata in Utah and New Mexico. These dicotyledonous stems are assigned to Munzingoxylon delevoryasii...
Part 3: Ecosystems and Mesozoic Plants
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13. Palynological Evidence for Conifer Dominance within a Heterogeneous Landscape in the Late Jurassic Morrison Formation, U.S.A.
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Eight palynological samples from a broad geographical range of the upper part of the Morrison Formation have yielded a rich palynoflora of over 100 morphospecies of bryophytes, lycophytes, sphenophytes, ferns, and seed plants. In striking contrast to Morrison megafloras, conifers are dominant throughout the palynoflora...
14. Mesozoic Plants and Dinosaur Herbivory
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For most of their existence, herbivorous dinosaurs fed on a gymnospermdominated flora. Starting from a simple reptilian herbivory, ornithischian dinosaurs evolved complex chewing dentitions and mechanisms, while sauropodomorph dinosaurs retained the primitive condition of not chewing. Some advanced theropod dinosaurs evolved a bird-type herbivory with a toothless beak and a gastric mill. Dinosaur digestive tract remains, coprolites, and other trace fossils offer...
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Page Count: 424
Illustrations: 16 color illus., 84 b&w illus.
Publication Year: 2010
Series Title: Life of the Past