Superorder of mammals including anteaters, sloths, and armadillos
Xenarthrans
Temporal range: Late Paleocene –Recent, 60–0 Ma
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Scientific classification
Domain:
Eukaryota
Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Infraclass:
Placentalia
Superorder:
Xenarthra Cope, 1889
Orders and suborders
Order Cingulata
Order Pilosa
Suborder Folivora
Suborder Vermilingua
See text for more details
Red: anteater, yellow: armadillo, blue: sloth, orange: both anteater and armadillo, green: both armadillo and sloth, purple: anteater, armadillo and sloth
Xenarthra (/zɛˈnɑːrθrə/; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos.[1] Extinct xenarthrans include the glyptodonts, pampatheres and ground sloths. Xenarthrans originated in South America during the late Paleocene about 60 million years ago.[2] 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.[3] Nearly all of the formerly abundant megafaunal xenarthrans became extinct at the end of the Pleistocene.
Xenarthrans share several characteristics that are not present in other placental mammals, and that suggest that Xenarthrans descend from subterranean diggers for insects. The name Xenarthra derives from the two ancient Greek words ξένος (xénos), meaning "strange, unusual", and ἄρθρον (árthron), meaning "joint",[4][5] and refers to their vertebral joints, which have extra articulations that are unlike other mammals. The ischium of the pelvis is also fused to the sacrum of the spine.[6] Xenarthran limb bones are typically robust, with large processes for muscle attachment. Relative to their body size, living xenarthrans are extremely strong.[7] Their limb bone structures are unusual. They have single-color vision. The teeth of Xenarthrans are unique. Xenarthrans are also often considered to be among the most primitive of placental mammals. Females show no clear distinction between the uterus and vagina, and males have testicles inside the body, which are located between the bladder and the rectum.[8] Xenarthrans have the lowest metabolic rates among therians.[9][10]
Xenarthran forms and lifestyles include:
Armadillos: Mostly small and some larger omnivores and insectivores with flexible banded body armor
Glyptodonts: Large herbivores with a rigid semi-spherical carapace
Pampatheres: Large herbivores (and possibly omnivores) with banded body armor
Anteaters: Small to large specialized feeders on social insects
Tree sloths: Medium-sized folivores specialized for life hanging upside-down in trees
Ground sloths: Medium to very large ground-living herbivores (and possibly omnivores)
Aquatic sloths: Thalassocnus, a medium-sized herbivore, is the only known aquatic sloth
^Vizcaíno, Sergio F.; Loughry, W. J., eds. (2008). The biology of the Xenarthra. Gainesville: University Press of Florida. ISBN 978-0-8130-3718-9. OCLC 741613153.
^O'Leary, M. A.; Bloch, J. I.; Flynn, J. J.; Gaudin, T. J.; Giallombardo, A.; Giannini, N. P.; Cirranello, A. L. (2013). "The placental mammal ancestor and the post–K-Pg radiation of placentals". Science. 339 (6120): 662–667. Bibcode:2013Sci...339..662O. doi:10.1126/science.1229237. hdl:11336/7302. PMID 23393258. S2CID 206544776.
^Woodburne, Michael O. (2010). "The Great American Biotic Interchange: Dispersals, Tectonics, Climate, Sea Level and Holding Pens". Journal of Mammalian Evolution. 17 (4): 245–264. doi:10.1007/s10914-010-9144-8. PMC 2987556. PMID 21125025.
^Bailly, Anatole (1981-01-01). Abrégé du dictionnaire grec français. Paris: Hachette. ISBN 978-2010035289. OCLC 461974285.
^Bailly, Anatole. "Greek-french dictionary online". www.tabularium.be. Retrieved May 2, 2020.
^Delsuc, Frédéric; Catzteflis, François M.; Stanhope, Michael J.; Douzery, Emmanuel J. P. (August 2001). "The evolution of armadillos, anteaters and sloths depicted by nuclear and mitochondrial phylogenies: implications for the status of the enigmatic fossil Eurotamandua" (PDF). Proc. R. Soc. Lond. B. 268 (1476): 1605–15. doi:10.1098/rspb.2001.1702. PMC 1088784. PMID 11487408. Archived from the original (PDF) on 2016-03-04. Retrieved 2013-01-04.
^Webb, S. David (2001). "Chapter 10: Mammalia 2: Xenarthrans". In Hulbert, Richard C. (ed.). The Fossil Vertebrates of Florida. University Press of Florida. p. 176. ISBN 0-8130-1822-6.
^Kleisner, K; Ivell, R; Flegr, J (2010). "The evolutionary history of testicular externalization and the origin of the scrotum". Journal of Biosciences. 35 (1): 27–37. doi:10.1007/s12038-010-0005-7. PMID 20413907. S2CID 11962872.
^Elgar, M. A.; Harvey, P. H. (1987). "Basal Metabolic Rates in Mammals: Allometry, Phylogeny and Ecology". Functional Ecology. 1 (1): 25–36. Bibcode:1987FuEco...1...25E. doi:10.2307/2389354. JSTOR 2389354.
^Lovegrove, Barry G. (2000). "The Zoogeography of Mammalian Basal Metabolic Rate". The American Naturalist. 156 (2): 201–19. doi:10.1086/303383. JSTOR 3079219. PMID 10856202. S2CID 4436119.
Xenarthra (/zɛˈnɑːrθrə/; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a major clade of placental mammals native to...
three major subdivisions or lineages of placental mammals: Boreoeutheria, Xenarthra, and Afrotheria. All of these diverged from common ancestors. 2022 studies...
species of which exist solely on sloths. Sloths belong to the superorder Xenarthra, a group of placental mammals believed to have evolved in the continent...
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...
Cingulata, part of the superorder Xenarthra, is an order of armored New World placental mammals. Dasypodids and chlamyphorids, the armadillos, are the...
anatomy with "edentate" mammals (now recognised as members of the order Xenarthra) in the collection of the Paris museum, correctly recognised that the...
share superorder Xenarthra (cladogram below) with the Cingulata (whose only extant members are armadillos). The two orders of Xenarthra split 66 million...
and Pampatheridae. Cingulata is itself within the basal mammal group Xenarthra, which includes an array of American mammal groups like Vermilingua (anteaters)...
sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. Ground sloths varied widely in size, with the largest, belonging to genera...
suborder of the order Xenarthra, while some more recent classifications regard Pilosa as an order within the superorder Xenarthra. Earlier still, both...
proposed clade of placental mammals containing the cohorts or superorders Xenarthra and Afrotheria. These groups originated and radiated in the South American...
DNA from the extinct South American giant glyptodont Doedicurus sp. (Xenarthra: Glyptodontidae) reveals that glyptodonts evolved from Eocene armadillos"...
Preptotheria is a superorder of placental mammals proposed by McKenna & Bell in their classification of mammals. The Linnean taxonomy of Preptotheria according...
also known by a number of indigenous names. Anteaters are part of the Xenarthra superorder, a once diverse group of mammals that occupied South America...
diverging cingulate (Xenarthra: Peltephilidae) from the Late Oligocene of Bolivia and considerations regarding the origin of crown Xenarthra. Bulletin of the...
Daniel G. (1998-09-01). "The Phylogeny of the Myrmecophagidae (Mammalia, Xenarthra, Vermilingua) and the Relationship of Eurotamandua to the Vermilingua"...
Scillato-Yané; Esteban Soibelzon (2015). "A Peculiar New Pampatheriidae (Mammalia: Xenarthra: Cingulata) from the Pleistocene of Argentina and Comments on Pampatheriidae...
some modern armadillo species, and they are classified in the superorder Xenarthra alongside sloths and anteaters. Being a glyptodont, it was a rotund animal...
This is a list of mammals of Texas. Mammals native to or immediately off the coast of the U.S. state of Texas are listed first. Introduced mammals, whether...
reveal three major groups or lineages of placental mammals, Afrotheria, Xenarthra, and Boreoeutheria. which diverged from early common ancestors in the...
Epitherians comprise all the placental mammals except the Xenarthra. They are primarily characterized by having a stirrup-shaped stapes in the middle...
touch their young without causing injury. Myrmecophagids belong to the Xenarthra, formerly known as Edentata, which also includes sloths and armadillos...
Ear Region of Edentates and the Phylogeny of the Tardigrada (Mammalia, Xenarthra)". Journal of Vertebrate Paleontology. 15 (3): 672–705. Bibcode:1995JVPal...
Storch, 2003 The order Pholidota was considered to be the sister taxon to Xenarthra (neotropical anteaters, sloths, and armadillos), but recent genetic evidence...
A list of prehistoric and extinct species whose fossils have been found in the La Brea Tar Pits, located in present-day Hancock Park, a city park on the...
This is a list of the native wild mammal species recorded in South America. South America's terrestrial mammals fall into three distinct groups: "old-timers"...
(November 2019). "A reappraisal of the phylogeny of Mylodontidae (Mammalia, Xenarthra) and the divergence of mylodontine and lestodontine sloths". Zoologica...
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