Notoungulata

an order of fossil mammals. Closely related to the Ungulata, the Notoungulata are referred to as the South American ungulates. They lived in the Paleogene and the Pleistocene. Some members of the order, such as the Tipoteria, had traits of both ungulates and rodents; others, such as the Entelonichia and Toxodontia, resembled rhinoceroses and tapirs. The Notoungulata ranged in size from that of a rabbit to that of a rhinoceros. They evidently evolved in Asia from the condylarths; in the early Paleogene they reached America, where they became widely distributed and evolved into many morphologically and biologically different groups.