47 million-year-old lizard fossil sheds light on missing link in snake origins

New research has provided evidence that the body shapes of snakes and limbless lizards evolved independently, ending the long-time debate on the snake’s origin. 
 
The researchers found a 47 million-year-old fossil of a lizard called Cryptolacerta hassiaca, which provides the first anatomical evidence to the findings.

"This fossil refutes the theory that snakes and other burrowing reptiles share a common ancestry and reveals that their body shapes evolved independently," said Johannes Müller, lead author and professor of Humboldt-Universität, Berlin.

The fossil also reveals that amphisbaenians are not closely related to snakes, but to lacertids, a group of limbed lizards from Europe, Africa and Asia.

The researchers used X-ray computed tomography to reveal the detailed anatomy of the lizard's skull and combined the anatomy of Cryptolacerta and other lizards with DNA from living lizards and snakes to analyze relationships.

The results showed that the Cryptolacerta shared a thickened, reinforced skull with worm lizards and both were most closely related to lacertids.

Whereas, snakes were related to monitor lizards like the living Komodo dragons.