Creodonts and mesonychids hold the carnivore niche
Archaic meat-eaters dominate first — including hoofed predators with skulls a metre long.
- When
- —
- Duration
- 21 million years
- Known to
- ± 2 million years
- Era
- Eocene, Cenozoic
Before modern carnivorans take over, the predator roles belong to the creodonts, whose shearing carnassial teeth are formed from different molars than those of cats and dogs, and to the mesonychids, hoofed predators with crushing teeth. Andrewsarchus, known from a single enormous skull, may have been the largest carnivorous land mammal ever. Both groups decline through the later Eocene and are gone by the Miocene; the creodont tooth arrangement, with its shearing pair set further back, allowed less flexibility as diets changed.