Fossil remains for Sahelanthropus tchadensis have been found in the north African Djurab desert in Chad.

S. tchadensis is very primitive but also exhibits advanced canine reduction, significantly reduced prognathism, and lacks a honing complex. Position of the foramen magnum suggests S. tchadensis was bipedal, which, if true, makes this specimen the oldest evidence of hominin bipedalism. S. tchadensis’ prominent brow ridge unique among early hominins until 5 million years later with Homo erectus.

S. tchadensis lived at the same time as the last common ancestor to apes and humans, but its relationship to later hominins remains ambiguous.

The type specimen for S. tchadensis, TM 266-01-060-1 or the Toumai specimen, dates between 6 and 7 million years old. Toumai means “Hope for life” in the Goran language.