Until Now
GeologyBiologyEnvironment

The Pebas mega-wetland

A million square kilometres of swamp and lake covers western Amazonia, full of enormous crocodilians.

When
Duration
4.5 million years
Known to
± 1 million years
Era
Miocene, Cenozoic

Andean uplift loads the crust and the foreland subsides, creating a vast long-lived wetland of swamps, lakes and rivers across western Amazonia, periodically invaded by the sea from the north. It persists for several million years and supports an extraordinary aquatic fauna, including at least a dozen coexisting crocodilian species — more than anywhere on Earth today — alongside giant turtles and freshwater rays that still betray their marine ancestry.

Just before

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