A “peculiar” reptile from the age of dinosaurs is challenging assumptions about how ancient crocodile relatives moved. This small Triassic animal may have begun life on four legs before shifting to a two-legged stance, a rare developmental change among reptiles. The species, Sonselasuchus cedrus, belonged to a group known as shuvosaurids, an unusual branch of crocodile-line archosaurs. 

Despite their lineage, many of these animals bore a striking resemblance to fast-running, ostrich-like dinosaurs called ornithomimids. Both groups lived side by side during the Late Triassic period (225-201 million years ago), long before modern crocodiles took on their familiar body plan.