Africa dries and opens
East African forest gives way to grassland and scrub, and the hominins in it change with the landscape.
- When
- —
- Duration
- 320 thousand years
- Known to
- ± 200 thousand years
- Era
- Pliocene, Cenozoic
Dust flux off Africa recorded in Atlantic and Indian Ocean cores steps up sharply around 2.8 million years ago, and soil carbonates and fossil faunas both record a shift toward open, seasonal, grass-dominated habitat. The forcing is global cooling combined with rift uplift blocking moisture. The timing is conspicuous: the earliest Homo, the first Paranthropus, and the oldest Oldowan tools all appear within a few hundred thousand years of this shift, and the savanna hypothesis rests on that coincidence — though the correlation is stronger than the demonstrated causation.