Astrapotheria is an extinct order of South American hoofed animals. The history of this order is enigmatic, but it may taxonomically belong to Meridiungulata (along with Notoungulata, Litopterna and Pyrotheria). In turn, Meridungulata is believed to belong to the extant superorder Laurasiatheria. However, some scientists regard the astrapotheres (and sometimes the Meridiungulata all together) to be members of the clade Atlantogenata. An example of this order is Astrapotherium magnum. When alive, Astrapotherium might have resembled a mastodon, but was only three meters (ten feet) long.