The longest recovery
Ecosystems take five to eight million years to rebuild — the slowest recovery from any extinction.
- When
- Known to
- ± 500 thousand years
- Era
- Triassic, Mesozoic
Anoxia and extreme warmth persist long after the eruptions stop, and further extinction pulses in the Early Triassic repeatedly knock back the survivors. Complex marine ecosystems do not reassemble for at least five million years, and some estimates run to eight or ten. Explaining that delay remains a central problem: the kill mechanism is better understood than why the world stayed broken for so long afterwards.