Sahelanthropus, the oldest possible hominin
A skull from Chad, seven million years old, has a foramen magnum positioned as if it walked upright.
- When
- —
- Duration
- 400 thousand years
- Known to
- ± 300 thousand years
- Era
- Miocene, Cenozoic
Sahelanthropus tchadensis is known from a distorted cranium nicknamed Toumai and some jaw and limb material, found far west of the Rift Valley in what was then a lakeshore beside encroaching desert. Its small canines and the forward position of the foramen magnum — where the spinal cord enters the skull — have been read as evidence of bipedalism and hominin status. A femur from the same site has been argued both ways. If it is a hominin, it sits within a million years of the split itself.