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.
Prosimian
While primates are often thought of as fairly intelligent animals, the prosimians are not very large-brained compared to other placental mammals. Their brain-cases are markedly smaller than those of simians of comparable sizes. In the large-eyed tarsiers, the weight of the brain is about the same as that of a single eye. Prosimians generally show lower cognitive ability and live in simpler social settings than the simians. The prosimians with the most complex social systems are the diurnal lemurs, which may live in social groups of 20 individuals. The nocturnal prosimians are mainly solitary.