Sorry, sea serpents. Snakes, it seems, slithered off their lizard legs on land. A new analysis of a primitive snake fossil suggests that these animals emerged from a line of burrowing reptiles.
Snakes are in the same reptilian order that includes lizards, but just how and where they split off to live their legless lives has been a bit of a mystery. Transitional fossils showing the move from four-legged lizard to belly-crawling snake have remained scarce. However, that the jawbones of a Cretaceous snake from North America suggest that it might be the earliest snake on record. And this serpent was terrestrial, clearing up decades of debate about whether snakes evolved for swimming or slithering, researchers reported online July 25 in Nature (Scientific American is part of Nature Publishing Group).