In 1982, David Pilbeam published a description of a significant fossil find — a large part of the face and jaw of a Sivapithecus. The specimen bore many similarities to the orangutan skull and strengthened the theory (previously suggested by others) that Sivapithecus was closely related to orangutans.
Sivapithecus was about 1.5 metres (4.9 ft) in body length, similar in size to a modern orangutan. In most respects, it would have resembled a chimpanzee, but its face was closer to that of an orangutan. The shape of its wrists and general body proportions suggest that it may have spent a significant amount of its time on the ground, as well as in trees. It had large canine teeth, and heavy molars, suggesting a diet of relatively tough food, such as seeds and savannah grasses.