Snakes evolved in water and then came onto land right? Well that has been the notion for years. A new study, however, questions that notion and says t
Snakes evolved in water and then came onto land right? Well that has been the notion for years. A new study, however, questions that notion and says that snakes started on land and mostly stayed on land, losing their limbs during their evolution.
Yale University researchers Daniel J. Field and Allison Y. Hsiang said the ancestor of all snakes was probably a nocturnal hunter that lived 120 million years ago, had tiny hind limbs that were essentially useless that came via another ancestral reptile.
"They probably weren't using them in locomotion in any way, but they did probably still have vestigial hind limbs stuck on the back of their bodies," Hsiang told NPR.
The fossil records of snakes have not been too promising to tell their story due to the fact that snake fossils tended to be smaller and more fragile than those of larger organisms. In the last 10 years however, a trove of new snake fossils have been unearthed that tell a new story about the evolution of this most misunderstood reptile family. These fossils tell more than the fact that they came from an ancient snake. The new fossils were analyzed along with living snakes to try and find the most recent common ancestor. In all they looked at 73 snake species, 15 of which were fossil species.
What the data determined was that snakes originally moved about on the ground like most do today and not in water, and went into burrows of other animals to find food.
"Snakes probably did not evolve, originally, to be in water," Hsiang said. "That's not why they developed this body plan; that's not what the earliest snakes were doing."
Their finding was supported by the earliest known snake fossils, Coniophis, Najash, and Dinilysia, all of which are terrestrial species.
They note that not a whole lot has changed between the ancestral snakes and the more than 3,000 species that exist today. They do say that the ancestral snakes could not manipulate prey items like snakes of today nor did they have the capability to constrict prey like constricting snakes such as boa constrictors and pythons. They lived in warm, humid and well vegetated environments and likely ate soft bodied vertebrate and invertebrates that were smaller in size than the snake’s head.
The complete study can be read or downloaded on the BMC Evolutionary Biology Journal website.
John B. Virata keeps a western hognose snake, a ball python, two corn snakes, a king snake, and two leopard geckos. His first snake, a California kingsnake, was purchased at the Pet Place in Westminster, CA for $5. His first pet reptile was a green anole that arrived in a small box via mail order. Follow him on Twitter @johnvirata