Ph.D., University of California at Berkeley, 1994; Professor Emeritus
Dr. McCrossin is a biological anthropologist whose interests include the following topics: fossil evidence for human evolution; paleoanthropology of Africa (study of human origins that comes from integration of evidence from biological anthropology and paleolithic archaeology); the ecology, behavior, and adaptive history of non-human primates; dietary and locomotor adaptations; paleoecology.
Dr. McCrossin has carried out field research in Africa since 1982, working in Kenya since 1987. His current research is devoted to understanding the phylogenetic relationships, adaptations and ecology of African ape and human ancestors from the middle and late Miocene (between 15 and 5 million years before present), especially a long-misunderstood genus called Kenyapithecus. Kenyapithecus was once thought to be a direct ancestor of humans and more recently an archaic great ape, but Dr. McCrossin’s research shows that in fact Kenyapithecus is the common ancestor of humans and our closest living relatives, the gorilla, bonobo, and chimpanzee. In addition, new discoveries from Maboko Island made by Dr. McCrossin reveal that Kenyapithecus possessed craniodental adaptations like those seen in living pitheciine monkeys (bearded sakis and uakaris) for eating hard fruit and nuts and limb bones adapted for a knuckle-walking mode of semi-terrestrial locomotion. Due to its phylogenetic position as common ancestor to gorillas, chimpanzees, and humans, Kenyapithecus proves that the earliest human ancestors passed through a knuckle-walking phase in their evolutionary history. Detailed descriptions of these recent discoveries are in preparation, based on comparisons to specimens of extant and extinct primates in museums in Africa, Europe, and the United States. In the future, Dr. McCrossin plans to continue African field research, in pursuit of information concerning the ecology and adaptations of the ancestors of the australopithecines and other primates from the Plio-Pleistocene.