My research interests are centered on studying the evolution of Old World Cenozoic mammals, particularly Afro-Arabian afrotheres and catarrhine primates. Paleontological and geological fieldwork has taken me to Turkey, Uganda, Ethiopia, Democratic Republic of Congo, Tanzania, Egypt, Pakistan, Kenya, China, and the western United States, and I have engaged in specimen-based museum study of fossil and extant mammalian collections in France, the United Kingdom, South Africa, Ethiopia, Pakistan, Egypt, Kenya, Tanzania, Uganda, Turkey, China, and throughout the United States. I received my professional training in anthropology at the University of Chicago (A.B., 1979) and in paleoanthropology at New York University (M. Phil., 1990; Ph.D., 1995), where I studied primate paleobiology and functional morphology under the supervision of Professor Terry Harrison. My dissertation, Function, Allometry, and Evolution of the Australopithecine Lower Precaudal Spine, received an Outstanding Dissertation in Science Award (1995) from New York University. Since then, my research has largely involved the investigation of proboscidean evolution, paleoecology, and taxonomy, taphonomy of eagle- and chimpanzee-kill assemblages, embrithopod systematics, and evolution and functional morphology of early catarrhine primates. In 2010, I co-edited a comprehensive volume on the fossil record of African mammals, the Cenozoic Mammals of Africa (University of California Press), which received a PROSE Award from the American Publishers Awards for Professional and Scholarly Excellence, Single Volume Reference in Science. I also have scholarly interest in improving conservation and professional standards of methods and materials used in fossil preparation and curation, and have served as the Chair of the Preparators Committee and Chair of the Preparators (Hix) Grant Committee of the Society of Vertebrate Paleontology. In 2017, I was awarded the prestigious William W. Amaral Legacy Award by the Association for Materials and Methods in Paleontology in recognition of significant and lasting contributions to the field of paleontology and lifetime achievement as a teacher, advocate, innovator, and skilled practitioner.
My current research includes the study of late Eocene barytheres and moeritheres from the Birket Qarun Formation, Egypt; Oligocene moeritheres, elephantiform proboscideans, and basal deinotheres from the Fayum, Egypt, Chilga, Ethiopia, and the Shumaysi Formation, Saudi Arabia; earliest Miocene plesielephantiforms and elephantiform proboscideans from Nakwai, Kenya; description and paleoecology of fossil proboscideans from the early Miocene sites of Moroto, Uganda, and Buluk, Kenya; comparative morphology of early stegodonts (Proboscidea, Mammalia) from Zhaotong, China; occurrence and paleoecology of the last Elephas in Africa (at Natodomeri, Kenya); taxonomy, biogeography, and paleoecology of fossil proboscideans from the Siwalik Sequence, Pakistan; description, taxonomy, and paleoecology of fossil proboscideans from early Pliocene sites at Ileret and Turkwel, Kenya; phylogenetic and taxonomic implications of fossil palaeoamasids (Embrithopoda, Mammalia) and other new afrotheres from Turkey; and investigation of behavioral and evolutionary implications of adult facial ontogeny in Fayumian early Oligocene Aegyptopithecus zeuxis (Catarrhini, Primates). Future field and museum work are planned to investigate paleoecological contexts of hominoid- and early hominin-bearing sites in the Tugen Hills, Kenya, and at Woranso-Mille and in the Middle Awash, Ethiopia, and the feeding ecology of drought-stressed elephants at Tsavo and Samburu, Kenya. These research projects involve a large number of international colleagues and are highly collaborative.