Miocene xenarthrans

informal group of mammals (fossil)

Thalassocnus is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—T. antiquus, T. natans, T. littoralis, T. carolomartini, and T. yuacensis—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths, but they may have also been adapted to a terrestrial lifestyle. They have been found in the Pisco Formation of Peru, the Tafna Formation of Argentina, and the Bahía Inglesa, Coquimbo, and Ho

thumb|right|Closeup of hand, showing claws thumb|right|Closeup of skull

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.

Pampatheriidae (from the Pampas Plain, and Ancient Greek θηρίον (theríon), meaning "beast") is an extinct family of large xenarthran cingulates related to armadillos. They first appeared in South America during the mid-Miocene, and Holmesina and Pampatherium spread to North America during the Pleistocene after the formation of the Isthmus of Panama as part of the Great American Interchange. They became extinct as part of the end-Pleistocene extinction event, about 12,000 years ago.

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

thumb|left|Life restoration of Hapalops longiceps and Propalaehoplophorus australis thumb|left|Skeleton

Nothrotheriidae is a family of extinct ground sloths that lived from approximately 17.5 mya—10,000 years ago, existing for approximately . Previously placed within the tribe Nothrotheriini or subfamily Nothrotheriinae within Megatheriidae, they are now usually placed in their own family, Nothrotheriidae. Nothrotheriids appeared in the Burdigalian, some 19.8 million years ago, in South America. The group includes the comparatively slightly built Nothrotheriops, which reached a length of about . While nothrotheriids were small compared to some of their megatheriid relatives, their claws provided

Parapropalaehoplophorus is an extinct genus of comparatively small (compared to Glyptodon) species of glyptodont, extinct relatives of the modern armadillo. The sole species, P. septentrionalis, identified in 2007 from the fossilized remains of a specimen found in 2004, weighed approximately 200 pounds and had a shell covered by tiny circular bumps. It lumbered around northern Chile in the Chucal Formation, an area now dominated by the Andes mountain range, some 18 million years ago. Fossils of the glyptodont also have been found in Peru (Ipururo and Pebas Formations).

Neotamandua is an extinct genus of anteaters that lived in the Miocene to Pliocene in South America.

Propalaehoplophorus, also written as Propalaeohoplophorus, is an extinct genus of glyptodont, which lived in South America during the Early Miocene epoch.

Protamandua is an extinct genus of anteaters. Its closest living relatives are the giant anteater (Myrmecophaga tridactyla) and tamanduas (genus Tamandua). Fossils of Protamandua are restricted to the Santa Cruz Formation of Argentina. It may have been a common ancestor of Myrmecophaga and Tamandua.

Palaeomyrmidon is an extinct genus of anteater. Its closest living relative is the silky anteater (Cyclopes didactylus). Although the silky anteater is arboreal, Palaeomyrmidon lived on the ground. Palaeomyrmidon is known from a fossil skull that was found in the Andalhualá Formation of Argentina.

Promegatherium ("before Megatherium") is a genus of prehistoric xenarthrans that lived in Argentina, during the Late Miocene. This genus is regarded as closely related to the later, and more famous genus, Megatherium, hence the reference in the name. The first specimens of Promegatherium were originally described by the biologist Florentino Ameghino in 1883.

Imagocnus is an extinct genus of ground sloth from the Early Miocene (Burdigalian) Lagunitas Formation of Cuba.

Stegotherium is an extinct genus of long-nosed armadillo, belonging to the Dasypodidae family alongside the nine-banded armadillo. It is currently the only genus recognized as a member of the tribe Stegotheriini. It lived during the Early Miocene of Patagonia and was found in Colhuehuapian rocks from the Sarmiento Formation, Santacrucian rocks from the Santa Cruz Formation, and potentially also in Colloncuran rocks from the Middle Miocene Collón Curá Formation. Its strange, almost toothless and elongated skull indicates a specialization for myrmecophagy, the eating of ants, unique among the or

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.

Prepotherium is an extinct genus of megatheriid ground sloths that lived during the Miocene period. Fossils of Prepotherium have been found in the Collón Curá and Santa Cruz Formations of Argentina.

Scirrotherium is an extinct genus of pampatheres, a family of herbivorous cingulates, related to the similar but smaller modern armadillos, and with the now extinct glyptodonts, well-known from their shell-like armor. Its scientific name is derived from the Greek prefix "skiros-", "cover", and the suffix "-therion, "beast", while the name of the type species, hondaensis, honors the town of Honda, in the Tolima Department of Colombia. Scirrotherium is one of several genera of xenarthrans found in the La Venta fauna, dated from the Middle Miocene.

Thinobadistes is an extinct genus of ground sloth of the family Mylodontidae endemic to North America during the Miocene-Pliocene epochs (Hemphillian). It lived from 10.3 to 4.9 mya, existing for approximately .

Eleutherocercus was a genus of glyptodonts that lived during the Late Miocene and Early Pliocene in South America. Fossils of the genus have been found in the Huayquerian Ituzaingó Formation (E. paranensis) and the Montehermosan Monte Hermoso Formation (E. antiquus) in Argentina.

Macroeuphractus is a genus of extinct armadillos from the Late Miocene to Late Pliocene of South America. The genus is noted for its large size, with Macroeuphractus outesi being the largest non-pampathere or glyptodont armadillo discovered, as well as its specializations for carnivory, unique among all xenarthrans.

alt=Reconstruction of the glyptodont Boreostemma venezolensis. Artwork created with rapidograph and colored markers. Author: Edwin Chávez. |thumb|Paleoart of Boreostemma venezolensis. Created by Edwin Chávez "Disfrasaurio". Boreostemma is an extinct genus of glyptodonts from northern South America. Fossils assigned to the genus were first described as belonging to Asterostemma from southern South America, but have been placed in the new genus Boreostemma by Carlini et al. in 2008. The type species is B. pliocena. Fossils of Boreostemma have been found in the Honda Group of Colombia, in Peru an

Pelecyodon is an extinct genus of ground sloths from the Early Miocene (Santacrucian) of South America.

Prozaedyus is an extinct genus of chlamyphorid armadillo that lived during the Middle Oligocene and Middle Miocene in what is now South America.

Palaehoplophorus (also spelled, historically, Palaeohoplophorus) is an extinct genus of glyptodont. It lived from the Middle to the Late Miocene, and its fossilized remains were discovered in South America.