A little animal that washed out to sea 240 million years ago off the coast of what’s now Italy turns out to be the oldest known fossil of a lizard.
The identification pushes back the fossil record of snakes and lizards by about 75 million years, says Tiago Simões of the University of Alberta in Edmonton, Canada. He and colleagues used observations of the fossil, called Megachirella wachtleri, and of related living and extinct species plus genetic data to reconstruct the evolutionary history of squamates, the reptile group that today includes snakes and lizards, the researchers report in the May 31 Nature.
Previously, the oldest known squamate fossils dated back about to 168 million years ago. Adding M. wachtleri to the mix means that the squamates are so ancient that they arose before the mass extinction at the end of the Permian Period 252 million years ago, notes herpetologist and evolutionary biologist Jeff Streicher of the Natural History Museum in London who was not involved in the study. That cataclysm came the closest (yet) to wiping out life on Earth. How the ancestors of modern lizards and snakes made it is still a matter of debate.