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Adjunct Associate Professor,
Department of Botany and Microbiology |
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Associate Curator, Paleobotany and Micropaleontology,
Sam Noble Oklahoma Museum of Natural History |
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Associate Professor,
School of Geology and Geophysics |
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RESEARCH | ||||
Flowering plants (angiosperms) exploded across the global landscape over the last 145 million years, accumulating diversity (species) and gaining ecological dominance in many habitats. I am interested in the patterns and underlying processes responsible for this dramatic revolution in terrestrial ecosystems. Specifically, I study the earliest phase of the flowering plant radiation that occurred during the Cretaceous (~145-65 million years ago) focusing on paleoecological patterns, morphological evolution, and the impact of flowering plants on other components of plant communities. |
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CURRENT PROJECTS | ||||
1) | Description of mesofossil floras from the Atlantic and Gulf Coastal Plains (USA) | |||
Mesofossils are small, charcoalified or lignitized fossil flowers, fruits, seeds, leaves, etc. that preserve exceptional morphological and anatomical detail, often in three dimensions. Studied with scanning electron microscopy, these fossils provide information about the presence of species that are unlikely to be preserved in typical compression floras; many are new to science. In addition, the exceptional preservation of mesofossils permits the study of morphological evolution in early angiosperms and provides evidence of insect-plant interactions. Working with colleagues around the world, we are in the process of documenting the diversity of early angiosperms from several sites and searching for more. |
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2) | Using phylogeny to investigate the history of morphological evolution in heterosporous ferns | |||
In collaboration with Drs. Kathleen Pryer and Harald Schneider (Duke University), and funded by NSF, we are working to integrate the morphological characters of fossil water fern megaspores intoa combined morphological and molecular phylogeny of extant Marsileaceae and Salviniaceae to investigate the morphological evolution of this clade. Combined with geographic and stratigraphic data on other megaspores (of lycophytes), we also are investigating the timing and distribution of the water fern radiation that appears to be coincident with the flowering plant radiation. |
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Charcoalified fossil flower (scale bar = 1 mm) | Cretaceous megaspores from Maryland, Virginia, and Georgia, USA (scale bars = 100µm) | ||
© 2001 The Field Museum | © 2001 The Field Museum, ©2001 Sam Noble Oklahoma Museum of Natural History | |||
STUDENT OPPORTUNITIES | ||||
Students have the opportunity to conduct primary research related to the above projects, or on projects of their own design. Facilities at the University of Oklahoma for the study of Paleobotany and Paleopalynology (fossil pollen and spores) include: the extensive Leonard R. Wilson Collection of Micropaleontology and Paleobotany Collection at the Sam Noble Oklahoma Museum of Natural History (especially Carboniferous and Permian plant fossils, and ~15,000 reprints on paleobotany and palynology); the Robert Bebb Herbarium in George Lynn Cross Hall, the Laurence S. Youngblood Energy Library in Sarkeys Energy Center. The Samuel Roberts Noble Electron Microscopy Laboratory provides access to scanning and transmission electron microscopes, and the Museum of Natural History will soon have a new variable pressure scanning electron microscope (for uncoated specimens, including rocks, up 6" in diameter) installed. For more information see the School of Geology and Geophysics or Department of Botany and Microbiology webpages. | ||||
RECENT PUBLICATIONS | ||||
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