Sahelanthropus (Toumai)

In 2001, a team led by Michel Brunet found a nearly complete skull in the Djurab Desert of Chad, in central Africa, and its age was put at about 7 million years. The skull, catalogued as TM 266, was spotted by a student, Ahounta Djimdoumalbaye, and nicknamed Toumai. It was named Sahelanthropus tchadensis, the 'Sahel man from Chad'. It had a small brain, about 360 to 370 cubic centimeters, similar to a chimpanzee's, but its canine teeth were small and its face was relatively flat. The hole at the base of the skull, where the spine attaches, sits further forward than in apes, suggesting a more upright head posture.

Whether Sahelanthropus was a hominin, a member of the human line after the split from chimpanzees, is debated. Some researchers argue the skull shows features linked to upright walking, and in 2022 a study of a leg bone argued it walked on two legs as well as climbing, though others dispute that the bone belongs to the species or shows habitual bipedalism. Others see it as an ape, perhaps related to the ancestors of gorillas. It lived beside a lake with grassland and forest, so it fits the idea that early human relatives lived in mixed habitats.