Research

While formally trained as a paleontologist, at heart I am an evolutionary ecologist concerned with how organisms function and interact with their environment, with special focus on the Mesozoic. My primary research interests lie in reconstructing the ecology of extinct vertebrates that lack modern analogs and understanding how the ancient ecosystems in which these organisms lived were structured and functioned. Such work provides insight to how life evolved and responded to changing conditions through geologic time. Such paleoecological questions require a synthetic approach. I have utilized a wide variety of methods, including taphonomy, functional morphology, and paleobiogeography. Currently my work focuses on two areas: the functional morphology of unguals and structure of Early and Late Cretaceous terrestrial communities.

	Functional Morphology I have been exploring the functional morphology of vertebrate unguals (claws) using both traditional and geometric morphometrics. Published work on living avian raptors shows a strong correlation between claw shape and predatory behavior. Theropods demonstrate a similar diversity of body sizes, limb proportions, and claw morphologies. I am using geometric morphometrics to examine shape variation in unguals from a wide range of theropod and extant avian taxa. Significant differences in claw shape exist between major clades and include potential evolutionary patterns worthy of further study. Part of this work includes quantifying morphological relationships between the hard and soft tissue components of bird claws as a means to more accurately reconstruct theropod unguals for biomechanical research. This work leads to multiple future avenues of research, including exploration of ecological differences between theropod taxa, evolution of theropod limbs (especially with regards to the evolution of flight), and as an aid in identifying isolated unguals. This method has also proved useful in parsing ecological differences among extant felids based on ungual shape, paving the way for applications to extinct felids and possibly other fossil carnivorans. Continuing work on vertebrate unguals will identify common features in the form and function across diverse groups, further elucidating the ecology of extinct taxa.
	3D Imaging of Fossil Organisms I have worked for several years using laser scanning and photogrammetry to capture images and build models of various fossil organisms. In my lab I have a NextEngine 3D laser scanner. Recently I acquired a 3D printer to create physical models of the reconstructions created in my lab.
	Broad-scale Paleoecological Patterns The ecological dynamics of Mesozoic communities are poorly understood, especially in regard to the role(s) dinosaur morphological adaptations played in their ecology. To address this I use functional morphology to explore dinosaur ecology, community structure, and evolution. I have been applying a method called Ecological Structure Analysis (ESA), which uses functional morphology to create distinct ecological profiles for fossil assemblages. Such work is an important step in understanding the structure and function of dinosaur-dominated communities, for which no modern analogs exist. This method allows us to assess how communities have responded over time to taxonomic, climatic, and tectonic change. This work was published in PLoS ONE.
	Climate and Dinosaur Distribution I have done work combining GIS software, fossil databases, and climate models in studying broad-scale dinosaur biogeographic patterns. Combining these data enables one to assess the relationship between extinct vertebrate taxa and climatic conditions, such as temperature and precipitation, creating a climate envelope of conditions in which the taxa occur most often. We can assess the breadth of the climatic envelope at various taxonomic levels as well as track changes that point to potential ecological shifts and/or the evolution of new adaptations. Such an approach to reconstructing vertebrate paleoecology has yet to be carried out and may offer important insights. I am interested in using this method to study the relationship between vertebrate biodiversity patterns and climate conditions in the Mesozoic.
	Experimental Taphonomy Little is known regarding how environment-specific decay and diagenesis underground affect bone preservation. My dissertation project was the first to explicitly test the connection between environmental parameters and short-term processes critical in the decay and diagenesis of buried bone. I am interested in the chemical and physical changes remains undergo after burial. This provides the opportunity to study the microstructure of fossil samples at various stages of preservation and compare them to recent- and archeological-age specimens from analogous environments as well as the composition of their surrounding sediments. Applied to organic decomposition, such knowledge would help establish the causal factors behind environmental patterns of preservation in the fossil record. (click here for a description of my dissertation)