Scientists generally accept that, millions of years ago, snakes evolved from lizards. What isn’t as clear, however, is exactly how these reptiles wiggled their way into a legless, elongated form. Evolutionary scientists have tried to figure this out by first determining where early snakes lived — the idea being that, once we know their ecological origins, we’ll have a better sense of how they became living noodles. Marine, terrestrial, and “fossorial” environments have been the best contenders.
Fossorial animals, like badgers and mole salamanders, lead a life of burrowing. And according to new research coming out of the University of Helsinki, the earliest snakes were fossorial as well, making the transition as they evolved from surface terrestrial-dwelling lizards. This contradicts previous theories, like the idea that snakes lost their legs while underwater and eventually crawled to land years later.
It makes sense that they lost their legs after quitting aquatic environments as some of the semi-aquatic snakes still have vestigial limbs.