I study mammalian paleontology and evolutionary processes and theory. We use the basic information on groups of organisms (on morphology, phylogeny, chronology, geographic distribution, paleoenvironmental context) to test hypotheses of how those species and their special characteristics evolved.
The organisms about which I know most are in the Family Bovidae, antelopes and allies; and the animals studied by my recent and current graduate students range from alligators and dinosaurs, through birds, to mammal groups such as herpestids (mongooses), spiral-horned antelopes, and the large felid cats and sabretoothed cats. Analytical topics include anatomy, allometry, ontogeny, heterochrony, systematics, functional morphology, biogeography, paleoecology, and the context of paleoclimatic and other physical changes.
Most of our research is interdisciplinary. In collaboration with relevant colleagues it integrates, for example, paleontology with biology of living organisms and their molecular genetics, geochemistry, and paleoclimatology. We combine such information to study a range of larger questions. Examples include: How do new species originate? How does new organismal form and function evolve? How do the evolutionary changes relate to climatic changes? I have done fieldwork in various parts of the world, and all my students have the opportunity to be a part of field projects.