The first lizards
The lineage that becomes lizards and snakes — the most species-rich reptile group — branches off.
- When
- Known to
- ± 5 million years
- Era
- Triassic, Mesozoic
A Triassic fossil identified as a crown squamate pushes the origin of lizards and snakes back into the Middle Triassic, considerably earlier than the body-fossil record had suggested and closer to what molecular clocks predicted. Squamates go on to become by far the most diverse reptile group, with over 11,000 living species — more than birds.