Oligocene xenarthrans

informal group of mammals (fossil)

thumb|Skull of P. ferox Peltephilus, the horned armadillo, is an extinct genus of armadillo xenarthran mammals that first inhabited Argentina during the Oligocene epoch, and became extinct in the Miocene epoch. Notably, the scutes on its head were so developed that they formed horns. Aside from the horned gophers of North America, it is the only known fossorial horned mammal.

Euphractinae is an armadillo subfamily in the family Chlamyphoridae.

Mylodontidae is a family of extinct South American and North American ground sloths within the suborder Folivora of order Pilosa, living from around 23 million years ago (Mya) to 11,000 years ago. This family is most closely related to another family of extinct ground sloths, Scelidotheriidae, as well as to the extant arboreal two-toed sloths, family Choloepodidae; together these make up the superfamily Mylodontoidea. Phylogenetic analyses based on morphology uncovered the relationship between Mylodontidae and Scelidotheriidae; in fact, the latter was for a time considered a subfamily of mylod

Kuntinaru is an extinct genus of tolypeutine chlamyphorid armadillo which existed in Bolivia, during the Late Oligocene (Deseadan age). It is known from the holotype MNHN-SAL 1024, skull missing the apex of the rostrum and the paratype MNHN-SAL 3, second skull missing the apex of the rostrum, recovered from the Salla Formation, Salla, Department of La Paz, Bolivia. It was first named by Guillaume Billet, Lionel Hautier, Christian de Muizon and Xavier Valentin in 2011 and the type species is Kuntinaru boliviensis.

Pseudoglyptodon is a genus of extinct sloths from South America. The type species is Pseudoglyptodon sallaensis.

Peltephilidae (meaning "armor-liking") is a family of South American cingulates (armadillos) that lived for over 40 million years, but peaked in diversity towards the end of the Oligocene and beginning of the Miocene in what is now Argentina. They were exclusive to South America due to its geographic isolation at the time, one of many of the continent's strange endemic families. Peltephilids are one of the earliest known cingulates, diverging from the rest of Cingulata in the Early Eocene.