In February 2013, Fernando Garberoglio was searching for fossils in La Buitrera Paleontological Area, a vast region in Argentina’s Río Negro province. Then an undergraduate paleontology student at the Universidad de Buenos Aires, Garberoglio picked up an inconspicuous pebble, which, he was shocked to find, was in fact the well-preserved fossil of an ancient snake skull.

In the wake of this discovery, researchers uncovered multiple other snake fossils, including a total of eight skulls, reports CNN’s Ashley Strickland. The remains are around 95 million years old and belong to a prehistoric snake group known as Najash, after “nahash,” the Hebrew word for snake. It’s a fitting moniker, because like the crafty biblical creature that instigated the fall of man, Najash had legs—hind ones, at any rate.

Najash specimens were first described in 2006, based on a skull and partial skeleton fossils. The creature clearly had “robust hindlimbs,” something that had already been observed in ancient marine snake fossils, but Najash was unique because it was a terrestrial animal. But it was difficult for scientists to get a clear sense of what Najash’s head looked like, since the skull had been found in fragmentary condition.