This week, all eyes are on Pyeongchang, South Korea, where some of humankind's most talented athletes are gathered to make Winter Olympics history. But 110 million years ago, a muddy lagoon about 170 miles south of the 2018 games hosted athletic history of its own—by tracing tiny footsteps as a lizard sprinted on its hind legs.

The fossilized trackway, unveiled on Thursday in the journal Scientific Reports, is the oldest direct evidence of bipedalism, or moving on two legs, in lizards. More than 50 species of lizards today run on two legs; the new find reveals that the ability arose early on in lizard evolution.

“Footprint fossils provide direct evidence of an animal’s behavior, [which] skeletal fossils cannot do,”