I have a broad range of paleobiological interests centering on questions of mammalian evolutionary history. Phylogenetic analysis and the application of mammalian paleontology to geological problems are principal themes of my current research. Recent systematic work focuses on the evolutionary relationships between extinct South American "hoofed" mammals, marsupials, and rodents. My geologic interests center on several tectonic and stratigraphic questions in the Andean Main Range of central Chile.