My field and laboratory research is focused on paleobiological and biostratigraphic questions concerning the evolution of Mesozoic and Cenozoic terrestrial biotas. Currently I am studying the systematic interrelationships of Mesozoic mammals, making use of characters of both skeletal morphology and enamel microstructure. A stratigraphically controlled series of early Paleocene (Puercan) local faunas calibrated through 40Ar/39Ar age determinations provides the basis for analyses of the patterns and tempos of terrestrial faunal change during the first million years after the extinctions used to mark the end of the Cretaceous.
Graduate student research projects include: Investigation of the phylogenetic interrelationships, locomotor evolution, and turnover rates of Eocene artiodactyls; analysis of phylogenetic interrelationships and biogeographic distributions of Late Cretaceous and Early Cenozoic members of the Multituberculata; and study of the origins and evolutionary diversification of neornithine birds during the Late Cretaceous and Paleocene.
In the News
In an attempt to resolve the issue, scientists at the Berkeley Geochronology Center (BGC), the University of California, Berkeley, and universities in the Netherlands and the United Kingdom have now determined the most precise dates yet for the dinosaur extinction 66 million years ago and for the well-known impact that occurred around the same time.