The diversification of terrestrial tetrapodsOne of the most consequential transitions in vertebrate evolution was the transition for water-dwelling to land-dwelling tetrapods. I am currently using bone histology to better understand the life histories and biologies of early tetrapods from the Carboniferous (between 360 -390 million years ago). In revealing aspects to these animals' biology, I hope to shed light on how vertebrate life diversified on land.
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The evolution of the mammalian dentitionThe mammal dentition (e.g. prismatic enamel, complex tooth shape, single tooth replacement) is considered a hallmark of our evolutionary history. Yet, the story of how and when this dentition arose has not previously considered the entire 300 million years of evolution of our synapsid lineage. I research non-mammalian synapsids to find out when these traits first appeared, if there are correlations between traits, and if there are instances of convergent evolution that can tell us something about the selective pressures that gave rise to the mammalian dentition.
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Seasonality in the Early Triassic (220 million years ago) of AntarcticaAntarctica has not always been the ice and snow covered continent it is today. In fact, during most of the history of life on earth, it has been home to a variety of different plants and animals. Despite its warmer climates, the continent has remained in the polar circle and the life living there would have experienced extreme light and dark seasonality. I am interested in looking at any physiological adaptations Lystrosaurus, a non-mammalian synapsid, may have acquired to cope with living in such a seasonally stressed environment. I am looking at the tree-ring-like growth structures in their tusks to compare with other Lystrosaurus living in seasonally less stressed environments.
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Pathologies in the fossil recordThe nature of paleohistological work has led to a collection of specimens that had pathologies. I am interested in providing an evolutionary context for disease and pathology as well as exploring any insights these pathologies can provide about the biology of fossil vertebrates. This work includes a tumor in a 255 million year old gorgonopsian (saber-toothed mammal relative) and trauma to the ever-growing tusks of several dicynodont mammal-like relatives.
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Bone histologyI am interested in ground-truthing signals in modern bone histology to reconstruct the biology of extinct vertebrates. There are several factors that contribute to the microstructural details found in bone. In isolating how each of those factors influence bone I look to apply bone histology as a proxy for understanding factors like physiology, growth, and function in fossil vertebrates. This research currently includes sectioning modern emu and ostrich hatchlings to describe how hatching records in bone histology, assessing the role body size plays in determining the bone histology of small mammals, and how modern amphibian bone histology changes through ontogeny with different life histories.
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