Gigantopithecus blacki was, as its name implies, a gigantic ape from the Pleistocene of China. Its remains consist only of teeth and jaws, but these are of a tremendous size, with the largest specimens nearly twice the dimensions of male gorilla teeth and jaws. A similar, slightly smaller jaw is known from the Miocene of northern India, and has been called Gigantopithecus bilaspurensis (Simons and Ettel, 1970). Assuming that Gigantopithecus had the same proportion of tooth size and body mass as living apes, these Chinese remains suggest a body mass of over 400 kg for the largest individuals. The molars are relatively thicker than most living apes, and the overall body size may not quite have matched that of the jaws, but even so Gigantopithecus was the largest primate ever to exist.
With such a large body mass for a primate, Gigantopithecus must have spent most of its waking hours eating. It is likely that the giant ape depended on a steady diet of vegetative matter, and scientists speculate that bamboo made up the largest part of this diet. If so, Gigantopithecus may have a close analog in the living giant panda, which is not a primate but lives largely on bamboo today. The factors leading to the extinction of Gigantopithecus may be similar to those that threaten the panda, especially the fragmentation and loss of bamboo forest. Although Gigantopithecus and early humans may have coexisted for a period of time in China and Southeast Asia, there is no evidence that they interacted, or that humans led to the ape's extinction.