Fossil footprints show some crocodile ancestors walked on two legs
Fossil tracks preserved in a South Korean rock formation are the first footprint evidence that some ancient ancestors of modern crocodiles walked on two legs. The size and spacing of the 106-million-year-old tracks suggest the crocodylomorph was 2 to 3 meters long — a fearsome predator similar in size to its modern descendants, researchers report June 11 in Scientific Reports. The tracks were found in the fossil-rich Jinju Formation, home to the remains of a wide variety of animals including dinosaurs. It’s tough to identify a species from footprints, says paleontologist Martin Lockley of the University of Colorado Denver. “Short of finding the animal dead in its tracks, there’s always a little bit of uncertainty.” But the beautifully preserved prints made it possible to attribute them to Batrachopus, a genus of fossil tracks known to be made by crocodylomorphs. Perhaps the most surprising feature of the tracks is the utter absence of any manus, or hand, prints — strong evidence...