Discovered in Chad, Sahelanthropus tchadensis is aged at 6 to 7 million years old. This new hominid species, nicknamed Toumai, has caused great debate among scientist since this specimen appears to be more human-like than any other known fossil hominid in its age span yet still possesses several primitive primate features. Currently, it is still undetermined as to whether this species was bipedal or walked on all four limbs. This specimen may prove that human and chimpanzee lineages diverged earlier than previously thought.