Armadillos are New World placental mammals in the order Cingulata. They form part of the superorder Xenarthra, along with the anteaters and sloths. 21 extant species of armadillo have been described, some of which are distinguished by the number of bands on their armor. All species are native to the Americas, where they inhabit a variety of different environments.
Xenarthra is a major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Extinct xenarthrans include the glyptodonts, pampatheres and ground sloths. Xenarthrans originated in South America during the late Paleocene about 60 million years ago. They evolved and diversified extensively in South America during the continent's long period of isolation in the early to mid Cenozoic Era. They spread to the Antilles by the early Miocene and, starting about 3 million years ago, spread to Central and North America as part of the Great American Interchange. Nearly all of the formerly abundant megafaunal xenarthrans became extinct at the end of the Pleistocene.
Glyptodonts are an extinct clade of large, heavily armoured armadillos, reaching up to 1.5 metres (4.9 ft) in height, and maximum body masses of around 2 tonnes. They had short, deep skulls, a fused vertebral column, and a large bony carapace made up of hundreds of individual scutes. Some glyptodonts had clubbed tails, similar to ankylosaurid dinosaurs.
Cingulata, part of the superorder Xenarthra, is an order of armored New World placental mammals. Dasypodids and chlamyphorids, the armadillos, are the only surviving families in the order. Two groups of cingulates much larger than extant armadillos existed until recently: pampatheriids, which reached weights of up to 200 kg (440 lb) and chlamyphorid glyptodonts, which attained masses of 2,000 kg (4,400 lb) or more.
The six-banded armadillo, also known as the yellow armadillo, is an armadillo found in South America. The sole extant member of its genus, it was first described by Swedish zoologist Carl Linnaeus in 1758. The six-banded armadillo is typically between 40 and 50 centimeters in head-and-body length, and weighs 3.2 to 6.5 kilograms. The carapace is pale yellow to reddish brown, marked by scales of equal length, and scantily covered by buff to white bristle-like hairs. The forefeet have five distinct toes, each with moderately developed claws.
The order Pilosa is a clade of xenarthran placental mammals, native to the Americas. It includes anteaters and sloths. The name comes from the Latin word for "hairy".
Doedicurus is an extinct genus of glyptodont from South America containing one species, D. clavicaudatus. Glyptodonts are a member of the family Chlamyphoridae, which also includes some modern armadillo species, and they are classified in the superorder Xenarthra alongside sloths and anteaters. Being a glyptodont, it was a rotund animal with heavy armor and a carapace. Averaging at an approximate 1,400 kg (3,100 lb), it was one of the largest glyptodonts to have ever lived. Though glyptodonts were quadrupeds, large ones like Doedicurus may have been able to stand on two legs like other xenarthrans. It notably sported a spiked tail club, which may have weighed 40 or 65 kg in life, and it may have swung this in defense against predators or in fights with other Doedicurus at speeds of perhaps 11 m/s.
Megalonychidae is an extinct family of sloths including the extinct Megalonyx. Megalonychids first appeared in the early Oligocene, about 35 million years (Ma) ago, in southern Argentina (Patagonia). There is, however, one possible find dating to the Eocene, about 40 Ma ago, on Seymour Island in Antarctica. They first reached North America by island-hopping across the Central American Seaway, about 9 million years ago, prior to formation of the Isthmus of Panama about 2.7 million years ago. Some megalonychid lineages increased in size as time passed. The first species of these were small and may have been partly tree-dwelling, whereas the Pliocene species were already approximately half the size of the huge Late Pleistocene Megalonyx jeffersonii from the last ice age.
Acratocnus is an extinct genus of Caribbean sloths that were found on Cuba, Hispaniola, and Puerto Rico during the Late Pleistocene and early-mid Holocene.
Cabassous is a genus of South and Central American armadillos. The name is the Latinised form of the Kalini word for "armadillo".
Chaetophractus is a small genus of armadillos in the family Chlamyphoridae. It contains the following three species:
Dasypus is the only extant genus in the family Dasypodidae. Its species are known as long-nosed or naked-tailed armadillos. They are found in South, Central, and North America, as well as on the Caribbean islands of Grenada, Trinidad and Tobago. Members of Dasypus are solitary and primarily nocturnal to avoid temperature extremes and predation. They exist in numerous habitats ranging from brush to grassland areas and are mainly insectivorous.
Tolypeutinae is a subfamily of armadillos in the family Chlamyphoridae, consisting of the giant, three-banded and naked-tailed armadillos.
Euphractinae is an armadillo subfamily in the family Chlamyphoridae.
Pliometanastes is an extinct genus of ground sloths of the family Megalonychidae endemic to North America during the Late Miocene epoch through very early Pliocene epoch. Its fossils have been found in Costa Rica and across the southern United States from California to Florida.
Chlamyphoridae is a family of cingulate mammals. While glyptodonts have traditionally been considered stem-group cingulates outside the group that contains modern armadillos, there had been speculation that the extant family Dasypodidae could be paraphyletic based on morphological evidence. In 2016, an analysis of Doedicurus mtDNA found it was, in fact, nested within the modern armadillos as the sister group of a clade consisting of Chlamyphorinae and Tolypeutinae. For this reason, all extant armadillos but Dasypus were relocated to a new family.
Chlamyphorinae is a subfamily of South American armadillos in the family Chlamyphoridae. Members of this subfamily, the fairy armadillos, are largely fossorial and have reduced eyes and robust forearms with large claws for digging.
Nanoastegotherium is an extinct genus of cingulate, belonging to the family Dasypodidae, which includes the modern nine-banded armadillos. The name of the genus means "small Astegotherium", referring to its small size, smaller than the modern southern long-nosed armadillo, and to its affinities with Astegotherium, with which it forms the tribe Astegotheriini, within the family Dasypodidae. Its type species is Nanoastegotherium prostatum, whose species translates to "earlier" due to its age compared to Astegotherium.
