Modern birds diverge
The lineages behind every living bird split apart before the asteroid, and only they survive it.
- When
- —
- Duration
- 34 million years
- Known to
- ± 10 million years
- Era
- Cretaceous, Mesozoic
Neornithes — the crown group containing all living birds — originates in the Late Cretaceous, though how much of its diversification happens before the extinction is contested. Molecular clocks favour deeper Cretaceous splits; the body fossil record is sparse until afterwards. Vegavis, from Antarctica around 68 million years ago, is a genuine Cretaceous member of the waterfowl line and the strongest fossil evidence that modern groups were already present. Everything else with feathers — the enantiornithines, the toothed seabirds, the long-tailed forms — dies at the boundary.