Reconstruction of a lizard running bipedally while being chased by the pterosaur Pteraichnus koreanensis, based on the trackways found at the Hasandong Formation, South Korea. | Chuang Zhao

Lizards Ran for Their Lives on Two Feet During the Dinosaur Era

The oldest known lizard footprints show the animals ran on two feet, confirming a long-held view among researchers.

Photograph (left) and drawing (right) of the lizard trackways on the mudstone block | Hang-Jae Lee and Yuong-Nam Lee
Close-up images, as well as corresponding drawings, of two of the lizard trackways | Hang-Jae Lee and Yuong-Nam Lee
Illustration showing the lizard's estimated size and how it ran | Hang-Jae Lee and Yuong-Nam Lee