I am interested in a wide range of topics involving human and primate evolution. I am currently working with Michel Brunet and colleagues on the description and analysis of the new hominin from Chad, Sahelanthropus tchadensis, and I have long-term and continuing interests in the behavioral reconstruction and phylogenetic relationships of Miocene apes, which broadens to include more theoretical aspects of phylogenetics. Another long-term interest is the analysis of faunal change and its relationship to environmental change, in particular based on our extensive faunal record from the Neogene Siwalik Series of Pakistan. More recently I have become interested in evolutionary developmental biology, and particularly in the development and evolution of the anthropoid axial skeleton.