A bottleneck in vertebrate evolution
Almost every lineage of jawed fish is pruned away, and the survivors found the modern groups.
- When
- Known to
- ± 2 million years
- Era
- Devonian, Paleozoic
Analysis of vertebrate diversity across the Devonian–Carboniferous boundary shows the Hangenberg event was far more severe for jawed vertebrates than the earlier Kellwasser crisis. Placoderms vanish, most early tetrapod lineages disappear, and the survivors — a handful of sharks, ray-finned fish and tetrapods — radiate into the emptied world. Every living jawed vertebrate descends from that narrow group.