Gigantopithecus
Gigantopithecus (from the Ancient Greek ' "giant", and ' "ape") is an extinct genus of ape that existed from perhaps nine million years to as recently as one hundred thousand years ago, at the same period as "Homo erectus" would have been dispersed, in what is now India, Vietnam, China and Indonesia placing "Gigantopithecus" in the same time frame and geographical location as several hominin species. The primate fossil record suggests that the species "Gigantopithecus blacki" were the largest known primates that ever lived, standing up to and weighing as much as , although some argue that it is more likely that they were much smaller, at roughly in height and in weight.
Biretia
The smallest of the species, "B. fayumensis", had an estimated weight of 273 g, while the largest, "B. megalopsis", had a weight of about 376g. Adaptations of the skull of "B. megalopsis" are easily comparable to the modern tarsiers, a small, modern Asian primate with a nocturnal insectivorous lifestyle. We can infer the possibility of a nocturnal lifestyle for "B. megalopsis"' from the animal's molar roots, which are truncated to accommodate for large eye sockets typical of a nocturnal primate. The large eye structure and similarity to the modern tarsiers also suggests that it has lost its tapetum lucidum. Thus, "B. megalopsis" demonstrates itself as being the oldest known nocturnal primate.