I study fossil mammals in order to address questions surrounding the first appearance and early evolution of the modern orders of mammals. A major emphasis is the interval from the terminal Cretaceous through the early Eocene, which includes the evolution and diversification of “archaic” mammals following the extinction of the dinosaurs (ca. 65 mya), and the first appearance of nearly one-half of the modern orders of mammals, several appearing coincident with rapid, large-scale, global warming at the Paleocene-Eocene boundary (ca. 55 mya). Specific research topics include: (1) the response of mammal communities to climate change; (2) use of phylogenetic methods to infer hypotheses of relationships; and (3) use of functional morphology in order to study the evolution and paleoecology of small mammals. I am currently doing related field-based research in the Paleocene and Eocene of the Clarks Fork, Bighorn, and Crazy Mountains basins of Wyoming and Montana, and the Cerrejon and Bogota formations of northern Colombia.
- Fieldwork related to active research projects and collections acquisition in Florida, Wyoming, Montana, Indonesia, Central and South America
- Director of the Program of Vertebrate Paleontology