The Hangenberg event
The Devonian ends with a second catastrophe that finishes the armoured fish for good.
- When
- Known to
- ± 1 million years
- Era
- Devonian, Paleozoic
Around 358.86 million years ago, anoxia — including euxinic conditions reaching up into the sunlit surface layer — sweeps the oceans again. Placoderms are eliminated entirely, and jawed vertebrates pass through a severe genetic bottleneck from which the modern groups of fish and tetrapods emerge. Glaciation and sharp sea-level fall accompany the crisis. It closes the Devonian and the Age of Fishes together.