The Sahelanthropus. The skull, four jaw fragments, and some teeth of this primate were found in the Toros Menalla Formation in the Djurab Desert of northern Chad. Radioisotope dating of animal remains from Lothagam deposit (the animals of the Lothagam deposit seem to be about the same type and age as those of the Sahelanthropus sites in the Toros Menalla Formation where Sahelanthropus was found) suggest an age of 6.5-7.4 million years for the Sahelanthropus remains. Brain size was probably about 360-370 cubic centimeters. The nose opening in the Sahelanthropus skull reaches down toward the bony palate at the midline (more like monkeys and gibbons than apes), so the Sahelanthropus may be older than the last common ancestor of all apes and humans.

Note that the Sahelanthropus remains were found in Chad, which is sometimes (misleadingly) described as “West Africa” in popular media accounts. Also, the Sahelanthropus skull and teeth show it to be an early ape like Oreopithecus. It’s hardly appropriate to call it an early “human” fossil.

We have used The Last Humans (2007) by G. J. Sawyer, Viktor Deak, Esteban Sarmiento, and Richard Milner as a source for this description.

1. The Sahelanthropus has its own web page.
2. A National Geographic page about the Sahelanthropus.
3. The Toumai skull is described at the Talk Origins website.
4. A CNN article about Toumai and the relationships between Sahelanthropus and humanity.

This work by Eric & Chun-Chih Hadley-Ives is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.