Yale researcher finds misssssss-ing link between snakes and lizards

Researchers at Yale have identified an ancient protosnake they describe as the "missing-link" between snakes and other lizards. Here, skulls, top to bottom: gila monster, Coniophis precedens (the protosnake), modern pipe snake. Credit: Nicholas Longrich.

File this one under "missing slink."

A Yale University researcher says he's identified the world's most primitive snake - an ancestral link between lizards and snakes that slithers like a snake but isn't able to unhinge its jaws.

"It has a little give in the middle of the lower jaw, but it doesn't have all the other hinges that snakes have," said Nicholas Longrich, a postgraduate fellow in Yale's department of geology and geophysics. "We argue that it was the feeding system that really allowed snakes to take off."

The "protosnake" is Coniophis precedens, a creature that lived 60 to 65 million years ago. Famed Yale paleontologist O.C. Marsh named the snake more than a century ago, but until now its only known fossil record consisted of a single vertebra.


"Before this, we didn't know what the rest of the snake looked like," Longrich said.

Longrich, reached by phone on a trip to Alaska, said he stumbled upon additional Coniophis precedens bones while examining other fossils at a museum in Berkeley, Calif. He was working on a project regarding lizard extinction at the time.

The snake specimens he found had been collected many years earlier, but hadn't been studied.

"Snake fossils are extraordinarily rare," Longrich explained. "They're very small and very delicate. They're kind of rare and cryptic."

An analysis of those fossils, as well as others in New Haven and museums in New York City indicated that they were from a primitive snake. All of the fossils originated in the floodplains in eastern Wyoming and Montana.

Longrich's research, published Wednesday in the journal Nature, also stakes a claim regarding the evolutionary history of snakes. Longrich and his colleagues, Yale professor Jacques A. Gauthier and Harvard University doctoral student Bhart-Anjan S. Bhullar, contend that snakes evolved from land-based animals rather than marine animals.

"We feel like we've made some advances in the evolutionary tree here," Longrich said. "This is significant."

Yet he cautioned that Coniophis precedens is not the direct ancestor of today's snakes. In fact, these snakes lived at the same time as other snakes that were more evolved.

"This one actually appears kind of late in the game. It's kind of a living fossil in its own time," Longrich said.
