Transitional Snake with Lizard Head Sheds Light on Origin [Nature&Planet 2012-07-26]
[Photo] Gila monster (top), Coniophis precedens (middle), and the modern pipe snake. Nicholas Longrich (Photo: Yale University)
Researchers have identified a transitional snake that evolved with a body of a snake and a head of lizard, according to a study.
A team of researchers studied the fossil remains of a transitional snake (Coniophis precedens) that evolved from the Late Cretaceous period of North America more than 145 to 65 million years ago.
The study helped to understand the origin of snakes and whether they originated in a marine or in a terrestrial environment and about their feeding mechanisms. It also gave insight into what prey did they feed on.
Researchers found that the coniophis precedens had a snake-like body and a lizard-like head, and are certainly not anilioids as previously thought. These transitional snakes were the most primitive known snake. They were small in size, had reduced neural spines, and their burrowing habits indicate that the snakes had evolved from the land-dwelling lizards in a terrestrial environment than in a marine region, the researchers wrote.
Though the snakes had the capability to swim, they did not adapt any features for it. The snake had a skull that was intermediate between lizards and the snakes. Unlike the modern snakes, these transitional snakes with elongated body had their upper jaws fixed firmly to the skull, thus preventing them from feeding on relatively large prey.
"It moves like a snake, but it doesn't feed like a snake," Nicholas Longrich, a postdoctoral fellow in Yale's Department of Geology & Geophysics and the lead author of a paper, said in a statement.
The snake is said to be a primitive one, but certainly not ancestors to modern snakes, according to the researchers.
"It's not the direct ancestor of modern snakes, but it tells us what the ancestor looks like," Longrich said, adding, "A lot of evolution happened around it."
The study is published in the journal Nature.