7 million years ago: earliest hominid fossil.
Michel Brunet, a French paleontologist, and his team found in 2001, in an area called Sachel, in Chad, the remains of a hominid that lived 7 million years ago. Hence the fossils name: Sahelantropus tchadensis. It was also nicknamed Toumai, which means Hope of Life in the local language.
This fossil is dated before the divergence of species that gave rise to humans and chimpanzees, estimated to have happened between 6.3 and 5.4 million years ago.
There is controversy about whether Toumai is indeed a human ancestor or not, since it was found far west of the Great Rift Valley, the place known as the Cradle of Humankind.
Nevertheless, this is a hominid with both human and chimpanzee features, but it is unclear whether it was bipedal. Existing fossils of 9 individuals have been found, which include skulls, pieces of jaws and teeth.
Currently, there is one single living species of hominids, us humans, but there is no doubt that since their first appearance in the Miocene, at least 20 different species have existed.