Scientists have known for a long time that the ancestors of modern snakes had legs, but they never saw the snakes with actually functional limbs. A new paper published in Science introduces the world to Tetrapodophis amplectus a new species of snake that lived about 113 million years ago. While most of its body is very snake-like, it also has four tiny legs that would have been too weak to support its weight.
The fossil is 19.5 cm long, but the legs are less than a centimeter. They are positioned very near to the head and tail, where modern snakes have small notches instead of legs.
According to researchers, the legs have very well-defined fingers and claws, which would have made them good for digging and grasping prey. These were not simply vestigial features for T. amplectus.
While it has legs, the snake’s other features are surprisingly similar to its modern descendents. It has a long, flexible spine, malleable jaw, hooked teeth, and scales. It doesn’t have any features that indicate aquatic living, which is yet more evidence against the idea that snakes evolved as aquatic reptiles before moving onto land.
The T. amplectus fossil was noticed by Dr. Dave Martill on a trip to a museum in Solnhofen, Germany where it was displayed as “unknown fossil.” It was in a private collection for decades before it was acquired by the museum, and no one recognized the significance of it until Dr. Martill happened to realize, hey, that snake has legs. These legs might have been useful for T. amplectus, but they weren’t useful enough to be retained by successive generations.