July 27, 2012
Fossils Suggest Snake Evolution Occurred On Land, Not Sea
redOrbit Staff & Wire Reports - Your Universe Online
New analysis of what is being called one of the most primitive snake fossils ever discovered suggests that the reptilian creatures may have developed their unique look on land, not in water.
Nicholas Longrich of Yale University and his colleagues studied recently discovered fossils of the Coniophis precedens, an ancient protosnake that lived alongside dinosaurs some 65 to 70 million years ago, according to BBC News reports.
Those fossils, which were uncovered nearly a century ago in eastern Wyoming, demonstrate that the creature had lived in a floodplain environment and did not have the specific biological adaptations necessary for aquatic movement.
Furthermore, Longrich's team found that the Coniophis, which was approximately 24 inches long, had the body of a snake and the head of the lizard, making it a sort of "transitional snake," according to the Daily Mail's Rob Waugh.
"While the snake had been described in the scientific literature and remains had previously been collected, those studies had only looked at vertebrae," explained Jon Bardin of the Los Angeles Times. "In the new report, researchers“¦ analyzed the upper and lower jawbones of the snake as well as its vertebrae, and came to the conclusion that the snake was transitional because its head was more similar to a lizard´s than a snake."
Bardin said that the researchers concluded that the snake lacked the ability to swallow its prey whole by unhinging its jaw, meaning that it most likely ate small vertebrates. They also said that they believe that snakes did not begin to rapidly diversify until they developed their flexible jaws and gained the ability to swallow larger animals.
Their work has been detailed in the journal Nature.
In an interview with Eric Gershon of Yale News, Longrich called Coniophis precedens " the missing-link snake" and "the 'Lucy' of snakes," referring to the Australopithecus afarensis skeleton that was discovered in 1974 and provided evidence that bipedalism was linked to brain size during the evolutionary process.
"Compared to what we knew before, this is now one of the better-known snakes from the Cretaceous period, 145 million to 65 million years ago," he added. “It´s not the direct ancestor of modern snakes, but it tells us what the ancestor looks like“¦ a lot of evolution happened around it."
Image 2 (below): Gila monster (top), Coniophis precedens (middle), and the modern pipe snake. (Illustration by Nicholas Longrich)