Origins of Snake Ancestors Lengthened by Aeons, New Found Fossils Now Date as Far Back a 167 Million Years

According to research published Tuesday in Nature Communications, we may need to slither back the clock on snake evolution.

In fact, we may have been pretty wrong about just how snakes evolved from the common ancestors they share with modern lizards. Until now, the oldest-known snake fossils were only about 100 million years old. The new study presents not one, but four new specimens that are much older -- dating back as many as 167 million years -- found in neglected museum collections around the world. And these older fossils show the long, thin skulls that distinguish snakes from lizards today. Many scientists previously believed that snakes became long and limbless before they evolved their distinctive heads.

"The skulls of these animals are much more snakelike than even I thought they would have been," said study author Michael Caldwell, a paleontologist at the University of Alberta. "Which means that this quality of snake-ness had clearly occurred much earlier than we'd thought."

That's not so shocking when you look at lizard evolution.

"We can recognize that most of the major groups of lizards were already present at the time," he said. So it seems that snakes were evolving at much the same pace, as opposed to undergoing some rapid deviation from lizards 100 million years ago.

The new fossils are just small fragments of snake -- enough to show that they had snake-like heads, but not much else. Caldwell feels fairly certain that they still have had four limbs at the time, but can't be sure.

Caldwell and his colleagues found the new specimens by digging through museum drawers instead of archaeological sites. Many museums have untapped fossil and skeleton collections just waiting for specialized researchers to examine them.

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http://www.washingtonpost.com/news/speaking-of-science/wp/2015/01/28/museum-fossil-find-pushes-snake-origins-back-by-65-million-years/