Prehistoric glyptodonts of the genus Doedicurus graze on grassy plains 25,000 years ago in what is today South America. In the background is a giant ground sloth of the genus Eremotherium. With a turtle-like shell five feet tall and weighing over two tons, Doedicurus was the largest known glyptodontid, an extinct family of heavily-armored herbivores related to modern armadillos. Doedicurus carried a large spiked tail that could have helped protect it from large predators and other Doedicurus.