Adinotherium. Illustration and photo-reconstruction of the South American ungulate walking through arid steppe. Adinotherium is an extinct mammal of the Toxodontidae family, found during the Miocene age. Unlike some members of the family its forelegs and rear legs were the same length, so the height at the shoulders and the pelvis were equal, which facilitated running. There are several species of Adinotherium. The largest of them, Adinotherium ovinum, reached 1.5 meters in length, with a height of about 80cm and weighed 120 kg.