How an ancient snake grasped prey: With its ... four legs

According to researchers, the newly-discovered Tetrapodophis amplectus may have been an ancestor of modern day snakes.

Courtesy of Nicholas Longrich
An artist's rendition of Tetrapodophis amplectus, which lived in the Cretaceous.
Courtesy of Nicholas Longrich
This remarkably intact Tetrapodophis amplectus fossil was unearthed in Brazil's Crato Formation.

These feet weren’t made for walking.

They were, however, made for grasping. Researchers say a newly discovered snake species may have used its four limbs to snag prey or grapple with mates. The new species, Tetrapodophis amplectus, was discovered in Brazil’s Crato Formation and described in the journal Science on Thursday.

According to co-author and University of Bath paleontologist Nicholas Longrich, T. amplectus lived during the Early Cretaceous, between 146 and 100 million years ago. Notable for its unusual set of four limbs, the skeleton was hailed by researchers as being "insanely complete."

"Every bone from the nose to the tail," Dr. Longrich told the Monitor. "Parts of the skull are missing, but the other side is buried in the rock. Hopefully a CT scan will uncover those."

So isn't this just an ordinary lizard? No – snakes and lizards are differentiated by skull shape and other anatomical features, not by the presence of limbs. Snakes, unlike lizards, do not possess eyelids, and lizards have external ears, while snake ears are internal. So while T. amplectus may look like a lizard, it is more closely related to modern snakes.

"If the limbs were useless vestiges, we would expect them to be a reduced and simplified version of a lizard’s limbs," Longrich says. "If they were for burrowing, they should be stout and powerful like a mole’s. Instead, they have very long, skinny fingers with the last bone in the finger being extremely elongate. That's typical of animals that use their digits for grasping."

Paleontologists have long debated whether early snakes had terrestrial or marine origins. According to Longrich, T. amplectus was probably not much of a swimmer.

"It has a long trunk and a short tail, as do burrowing lizards," Longrich says. "The vertebrae are low and broad, which is typical of burrowers. But it wasn't exclusively a burrower. It was preying on small amphibians and reptiles, and you don't find many of them underground. But it has the hallmarks of a burrowing lifestyle, so it appears to be descending from a burrowing lizard."

Researchers say this new finding could improve our understanding of snake evolution. For example, the discovery suggests that snakes may have originated on the supercontinent Gondwanaland, Longrich says.

"It tells us a number of things," Longrich says. "Snakes evolve from burrowers, not marine animals. Early snakes were carnivores and constrictors – constriction seems to be primitive for snakes, not advanced. And after they stopped using the limbs for walking, they used them to constrict."

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to