Fossil Sheds Light on Snake Mystery
by Patricia Cazares, age 14
For many years scientists have been puzzled by the origin of snakes. DNA analysis indicates that snakes are related to monitor lizards and iguanas. Snakes look more similar to worm lizards, an earthworm-like animal.
Now, a new study provides some clues. A report published in the scientific journal Nature, says that worm lizards are probably not related to snakes, as scientists previously believed. Instead, it appears that snakes are related to a group of limbed lizards called lacertids which are found in Europe, Africa and Asia.
Johannes Muller, a paleozoologist at the Natural History Museum in Berlin, and his co-authors, studied the skull of a fossilized lizard called Cryptolacerta hassiaca and compared it with the skull of living lizards and snakes by using a technique called X-ray computed tomography, known as CT scans.
The fossil, discovered in Messel Pit, a fossil site near Frankfurt and Unesco World Heritage Site, was less than three inches in length. The fossilized lizard is the only known specimen of its kind.
Based on these scans, the fossilized lizard’s skull has a thickened capsulelike skull without external ear openings, similar to worm lizards but unlike other lizards and modern snakes. These results suggest that the fossilized lizard was a relative of both worm lizards and lacertids.
[Sources: The New York Times; Nature]