South American native ungulates

Meridiungulata Temporal range: Paleocene–Holocene PreꞒ Ꞓ O S D C P T J K Pg N
Toxodon, a notoungulate
Thesodon, a litoptern
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Infraclass:	Placentalia
Clade:	†Meridiungulata McKenna 1975
Orders
†Astrapotheria †Litopterna †Notoungulata †Pyrotheria †Xenungulata

South American native ungulates, commonly abbreviated as SANUs, are extinct ungulate-like mammals of controversial affinities that were indigenous to South America prior to the Great American Biotic Interchange. They comprise five major groups conventionally ranked as orders—Astrapotheria, Litopterna, Notoungulata, Pyrotheria, and Xenungulata—as well as the primitive "condylarth" groups Didolodontidae and Kollpaniinae. It has been proposed that some or all of the members of this group form a clade, named Meridiungulata, though the relationships of South American ungulates remain largely unresolved. The two largest groups of South American ungulates, the notoungulates and the litopterns, were the only groups to persist beyond the mid Miocene. Only a few of the largest species of notoungulates and litopterns survived until the end-Pleistocene extinction event around 12,000 years ago where they became extinct with most other large mammals in the Americas, shortly after the first arrival of humans into the region.

Though most SANUs lived in South America, astrapotheres and litopterns are known from Eocene aged deposits in the Antarctic Peninsula^[1] and the notoungulate Mixotoxodon spread as far north as what is now Texas during the Pleistocene as part of the Great American Biotic Interchange.^[2]