History of Snakes: How They Lost Their Legs


A new study published in the journal Science Advances could finally solve the mystery of how snakes lost their legs. It might revolutionize our knowledge of the history of snakes. How exactly?

Well, first of all, scientists found a 90-million-year-old fossil of a Dinilysia Patagonica, an extinct genus of snakes from South America. This extinct species which is closely linked to modern snakes, reached lengths of 6-1o feet (1.8 -3 meters) and preyed on small animals.

Secondly, scientists from the University of Edinburgh and the American Museum of Natural History, CT-scanned the Dinilysia fossil and built computer models that revealed the tiny hidden structures inside the snake’s skull.

What did the scientists find?

The CT scans showed the ancient ancestor of our modern-day snakes had large spherical canals in their ears. This body feature is typically found in burrowing creatures such as moles, gophers or rabbits.

This amazing finding completely alters the history of snakes, as we know it. This new research suggests that snakes lost their legs when their ancestors evolved in order to live in burrows, and not to help them live in the ocean, as we were taught so far.

The scientists then compared the CT scans to scans taken of modern reptiles. This comparison revealed that the inner ears of the ancient snake are distinct to ancient and modern burrowing reptiles, and not to those of snakes that live in the sea or above ground. The inner ears contain sensory organs which control balance and hearing. These organs are located within a basked-like structure of 3 narrow semi-circular canals. Scientists revealed this basket-like structure was large and spherical in the extinct Dinilysia Pagagonica, and was a sign for burrowing. If compared to aquatic reptiles – these have smaller and less defined inner ears

This extraordinary study could help us fill the gaps in the history of snakes and their evolution. It could offer some clues to the hypothetical ancestral species from which all modern snakes came from, which was most probably a burrower.
