The desmostylians go extinct
The only entirely extinct order of marine mammals disappears from the North Pacific.
- When
- —
- Duration
- 1.5 million years
- Known to
- ± 1 million years
- Era
- Miocene, Cenozoic
Desmostylians persist along the North Pacific rim until roughly 10 million years ago and then vanish completely, leaving no descendants. Their disappearance coincides with the cooling of the middle Miocene and with the expansion of kelp and the diversification of sea cows and pinnipeds into overlapping coastal niches. Nothing quite like them has existed since — an entire way of being a marine mammal that was tried once and not repeated.