Ichthyosaurs get enormous, fast
Within three million years of entering the sea, marine reptiles are already whale-sized.
- When
- Known to
- ± 2 million years
- Era
- Triassic, Mesozoic
Cymbospondylus youngorum from Nevada, about 246 million years old, has a two-metre skull and a body over 17 metres. Ichthyosaurs reached whale-like proportions in a few million years, where whales took some 45 million to do the same — a striking difference in the tempo of body-size evolution, apparently fuelled by the rapid rebound of ammonoid and conodont prey after the extinction.