BERLIN (AP) — A giant, plant-eating creature with a beak-like mouth and reptilian features may have roamed the Earth during the late Triassic period more than 200 million years ago, scientists said Thursday.

In a paper published Thursday by the journal Science, Polish researchers claim their find overturns the notion that the only giant plant-eaters at the time were dinosaurs.

The elephant-sized creature, known as Lisowicia bojani after a village in southern Poland where its remains were found, belonged to the same evolutionary branch as mammals.

Similar fossils from so-called dicynodonts have...