Snakes have been slithering on Earth far longer than anyone ever realized. Scientists on Tuesday described the four oldest-known snake fossils — the most ancient of which was a roughly 10-inch-long (25-centimeter-long) reptile called Eophis underwoodi that lived about 167 million years ago.
The remarkable fossils from Britain, Portugal and the United States rewrite the history of snake evolution, pushing back snake origins by tens of millions of years. Until now, the oldest snake fossil dated from about 102 million years ago, said University of Alberta paleontologist Michael Caldwell, who led the study published in the journal Nature Communications.
Scientists say snakes evolved from lizards, and a number of previously discovered fossils of primitive snakes featured small back legs. Those described on Tuesday did not include entire skeletons, but the researchers say all four may have had some form of reduced forelimbs and hind limbs. That does not mean they walked. "It seems probable that they were slithering, so to speak, though the limbs might still have been used for grasping," Caldwell said.