The even-toed ungulates radiate
Pigs, camels, deer and their relatives spread — and one branch of them is already in the ocean.
- When
- —
- Duration
- 21 million years
- Known to
- ± 2 million years
- Era
- Eocene, Cenozoic
Artiodactyls walk on two central toes and eventually evolve the multi-chambered fermenting stomach that makes ruminants so efficient at extracting energy from tough plant matter. Their Eocene radiation produces the ancestors of pigs, camels, deer, cattle and antelope. Molecular data delivered a shock in the 1990s by placing whales inside this group, closest to hippos, which the Indohyus and Pakicetus fossils then confirmed anatomically — one of the cleanest agreements between molecules and bones on record.