My current research centers on the evolutionary history of Old World mammals and the biostratigraphy and biogeography of the African and Eurasian Neogene. This research has been shaped by the long fossil sequences of Pakistan. It attempts to answer general questions about the evolution of terrestrial ecosystems, the relationship between faunal change and global climatic and tectonic events, and the importance of biotic versus environmental factors on faunal change.
The faunal studies that I and others have been doing in Pakistan are based on stratigraphically well-documented fossil collections and broad systematic analyses that incorporate material from other sites in Africa and Eurasia. Our Siwalik project is now in its forty-fifth year. During this time a primary concern has been collecting and identifying fossils and working out the basic stratigraphic framework. These activities provide the most basic biostratigraphic and paleoecological data and relate them to the detailed information we are also collecting on the sediments and ancient depositional environments.
Systematic analyses of the fossil material are essential to all biostratigraphic and paleoecological studies, as they are the keys to recognizing the patterns of phylogenetic and geographic relationships, and aid in assessing paleoecological associations. My systematic work most recently has focused on fossils from the Oligo-Miocene, with emphasis on the ruminants, carnivores, and the now extinct creodonts.