Ardi walks in the woods
A 4.4-million-year-old skeleton walks upright but still has a grasping big toe — and no knuckle-walking at all.
- When
- —
- Duration
- 100 thousand years
- Known to
- ± 50 thousand years
- Era
- Pliocene, Cenozoic
Ardipithecus ramidus is known from a partial skeleton recovered in Ethiopia's Middle Awash and published in 2009 after fifteen years of preparation, the bones being too fragile to lift intact. It combines an upright-capable pelvis with an opposable big toe for climbing, small canines in both sexes, and a brain the size of a chimpanzee's. Crucially it shows no adaptation for knuckle-walking, which undercuts the long-standing assumption that our ancestors passed through a chimpanzee-like stage. It also lived in woodland, not open savanna.