Desmostylus Fossils

Desmostylus was a unique, extinct marine mammal that belonged to the order Desmostylia, a rare group of herbivorous mammals that lived from the late Oligocene to the late Miocene epoch, around 30 to 7 million years ago. Desmostylus and its relatives are notable for being the only known order of marine mammals that relied exclusively on four-legged, amphibious locomotion, with characteristics that set them apart from other marine mammals like whales, dolphins, and sirenians (manatees and dugongs).