Scientists have created the most comprehensive family tree of snakes to date, and the ancestor at the very top looked different than the snakes we know today in one noticeable way: It "had tiny hind limbs, with complete ankles and toes," says a Yale researcher in a post at Eureka Alert. The legs probably weren't at all useful in terms of getting around, however, he tells the New York Times. They were more like "remnants" of hind legs. Another key finding: The researchers say this ancestral snake evolved on land, not water. They think it was slithering around the Southern Hemisphere about 128 million years ago, hunting soft-bodied prey in the forest by night, reports LiveScience.
Unlike modern snakes such as boas or pythons, researchers don't think the first snake had the ability to constrict its prey or to eat anything bigger than its own head. But it swallowed its victims whole after snaring them with sharp little teeth, explains the Washington Post. The findings in the journal BMC Evolutionary Biology came from analyzing the bones and DNA of 73 species of snakes and lizards. The first snakes were hunting in the age of dinosaurs, but researchers think snakes thrived after the massive dinosaur extinction for a simple reason: They "were able to take advantage of the relatively empty landscape left behind by the dinosaurs," write the researchers in a blog post. (If a poisonous snake bites you, an opossum might be your savior.)