Ruminants take over
The four-chambered stomach arrives in force, and its owners begin displacing everything else.
- When
- —
- Duration
- 11 million years
- Known to
- ± 1 million years
- Era
- Oligocene, Cenozoic
Ruminants regurgitate and re-chew their food and ferment it in a forestomach where microbes break down cellulose, extracting far more energy from tough plant matter than a hindgut fermenter can. Through the Oligocene the early deer, tragulids and their relatives diversify rapidly, and after the Grande Coupure they spread into Europe. Their rise is the main reason the perissodactyls decline: two groups eating the same plants, one of them substantially more efficient.