Until Now
Biology

The hyaenodonts fade

The archaic carnivore lineage holds on in Africa and Asia, then loses the niche for good.

When
Duration
11 million years
Known to
± 1 million years
Era
Oligocene, Cenozoic

Hyaenodonts persist through the Oligocene, including the enormous African Hyainailouros, but their share of the predator guild shrinks steadily. Their carnassial shear is formed from molars further back in the jaw than the carnivoran arrangement, which locks more of the tooth row into cutting and leaves less room to adjust as prey and habitats change. It is a plausible reason a group that had held the carnivore role for 40 million years steadily lost it to animals with a more modular set of teeth.

Just before

Just after