Heptacodon is a genus of primitive ungulate that lived between the Eocene and Oligocene epoch of North America. In life, it would have resembled a small hippopotamus-like animal with a narrow skull and pig-like features. Heptacodon were probably bound to aquatic habitats, inhabiting swamps and shores of rivers and lakes. There, it probably fed on aquatic vegetation and roots.
Eocene to Oligocene
Fossils of Heptacodon curtus have been found in the United States of America and originated from the Oligocene epoch. It was a fairly small anthracothere, growing up to 1.2 meters in length and it weighted about 180 kg. At least four other species of Heptacodon are currently known.
O. C. Marsh. 1894. A new Miocene mammal. American Journal of Science 47(281):409