Four-legged fossil Snake is a world first

‘Hugging’ creature from Brazil shakes up picture of snake evolution.

Tetrapodophis amplectus: the ‘four-legged hugging snake’

The first four-legged fossil snake ever found is forcing scientists to rethink how snakes evolved from lizards.

Although it has four legs, Tetrapodophis amplectus has other features that clearly mark it as a snake, says Nick Longrich, a palaeontologist at the University of Bath, UK, and one of the authors of a paper describing the animal in Science.

The creature’s limbs were probably not used for locomotion, the
researchers say, but rather for grasping prey, or perhaps for holding on to mating partners. Such speculation inspired the snake’s name, which loosely translates as ‘four-legged hugging snake’

Tetrapodophis was originally found in the fossil-rich Crato Formation in northeastern Brazil several decades ago. But its legs can be difficult to see at first glance, and it languished in a private collection after its discovery, assumed to be unremarkable.

“I was confident it might be a snake,” says David Martill, a palaeobiologist at the University of Portsmouth, UK, who came across the find in 2012. “It was only after getting the specimen under the microscope and looking at it in detail that my confidence grew. We had gone to see Archaeopteryx, the missing link between birds and dinosaurs, and discovered Tetrapodophis, the missing link between snakes and lizards.”

Losing limbs

Dave Martill, University of Portsmouth
Despite these legs, this is definitely a snake.