Gigantopithecus is believed to be the largest primate to have ever lived. Although quadrupedal, when standing on its hind limbs, Gigantopithecus would have stood nearly ten feet tall and weighed around 1200 lbs. This prehistoric relative of modern orangutans lived between 1.3 and .3 MYA. This reconstruction of the skull of Gigantopithecus was made by Grover Krantz. Krantz, a professor at Washington State University, was a proponent of the idea that Gigantopithecus was a bipedal ape, moving mostly on two legs.