Snake with Legs: Snake Evolution Shows How These Ancient Reptiles Transitioned from Walking to Losing Their Legs

Snakes are the elongated wild animals that we know today that crawl and glide their way on land. However, it is not always like this as the ancestors of these reptiles once had legs as they roamed the Earth 100 to 150 million years ago, according to scientists. Although it is evident that it was due to the long process of evolution that a snake with legs lost their appendages, a raging debate is still ongoing if snakes' limbed ancestors lived in aquatic or terrestrial environments in the first place.

Some research suggests that a snake with no legs first appeared during the end of the Late Cretaceous period, a time before the Chicxulub asteroid killed all non-avian dinosaurs and most life on Earth during that time. It remains a mystery if whether the said mass extinction event somehow affected snake evolution. Yet, evolutionary biology tells us that body parts or morphological features either evolve or devolve over time, depending if both organism and nature deem it necessary or not.

How Snakes Lost Their Legs?

(Photo : Photo by sippakorn yamkasikorn on Unsplash)

This question has mystified scientists for millennia, as it is not similar to other evolutionary changes observed with other animals; like modern humans becoming bipedal or penguins losing their ability of true flight. The subject involves snakes with legs which they used to live and hunt their prey but only to lose it at a certain prehistoric period that no one knows when exactly.

Still, previous research over the past decade somehow offers an answer to the mystery. In a 2015 study published in the journal Science Advances, researchers discovered a reptile fossil dating back 90 million years ago. The fossil provided a clue as to how snakes lost their legs, suggesting that the ancestors of different snake species of today evolved to live and hunt in burrows.

The said findings support previous suggestions by some scientists that snakes did not lose their limbs to live in marine environments, including seas and oceans. With this, the prevailing evidence indicates that the legs of ancient snakes devolved for one simple reason: they no longer need them.

Also Read: First Snakes Likely Had Legs and Toes?

Snake with Legs Myth

What may be true millions of years ago is entirely different in contemporary times and we are talking about the snake with legs myth, a notion debunked by experts. This myth persists due to circulating inquiries that some snakes now may still have legs, or at least tiny ones. However, snake evolution proves otherwise that no snake is alive today that has retained their limbs.

Scientists assert that a contemporary snake moves by gliding its muscle-imbued body even without legs. This is made possible as the reptile stretches its body forward and pulls its rear, moving at a pattern that resembles the letter "S." In addition to moving on land, experts say that all snakes can swim and still use their motor mechanism in both shallow and deep waters.