A relatively small group of extinct South American ungulates, ranging from the late Paleocene to the late Miocene. They are customarily divided into two suborders: the late Paleocene–Eocene Trigonostylopoidea, and the early Eocene–late Miocene Astrapotheroidea. Eocene members of the order, such as Albertogaudrya, tended to be large animals and exhibited the enlargement of the canines characteristic of later astrapotheres.