AskDefine | Define edentate

Dictionary Definition

edentate adj : having few if any teeth; "anteaters are edentate animals" [syn: edental, edentulate] n : primitive terrestrial mammal with few if any teeth; of tropical Central America and South America

Extensive Definition

The superorder Xenarthra is a group of placental mammals (infraclass Eutheria), extant today only in the Americas. The origins of the order can be traced back as far as the early Tertiary (about 60 million years ago, shortly after the Mesozoic era). The presence of these animals in Central and North America is explained by the Great American Interchange.
Xenarthrans have the lowest metabolic rates among the therians.

Evolutionary relationships

It includes the anteaters, tree sloths, and armadillos, as well as the extinct ground sloths, glyptodonts and pampatheres. In the past, these families were classified together with the pangolins and Aardvark as the order Edentata (meaning toothless, because the members do not have front incisor teeth or molars, or have poorly-developed molars). It was subsequently realized that Edentata was polyphyletic—that it contained unrelated families and was thus invalid by cladistic standards. Aardvarks and pangolins are now placed in individual orders, and the new order Xenarthra was erected to group the remaining families (which are all related). The name Xenarthra means "strange joints", and was chosen because their vertebral joints have extra articulations and are unlike those of any other mammals. Because they lack characteristics believed to be present in the common ancestor of other known Eutherian mammals, morphological evidence suggests that the Xenarthra are outside the Epitheria, which contains all other known Eutherians today.
The morphology of Xenarthrans generally suggests that the anteaters and sloths are closest together within Xenarthra, which is upheld by molecular studies. The order Xenarthra is more and more often divided into two orders: Pilosa, containing the Vermilingua and Folivora (previously Tardigrada), and the separate order Cingulata. Xenarthra now has the rank of cohort or super-order. The Xenarthra are part of the super-cohort Atlantogenata.

Classification

SUPERORDER XENARTHRA

References

edentate in Bulgarian: Непълнозъби
edentate in Catalan: Xenartre
edentate in Czech: Chudozubí
edentate in Danish: Gumlere
edentate in German: Nebengelenktiere
edentate in Spanish: Xenarthra
edentate in Esperanto: Ksenartroj
edentate in Faroese: Jagldýr
edentate in French: Xenarthra
edentate in Croatian: Xenarthra
edentate in Italian: Xenarthra
edentate in Hebrew: דלשינאים
edentate in Georgian: არასრულკბილიანები
edentate in Lithuanian: Nepilnadančiai
edentate in Limburgan: Tanderme
edentate in Hungarian: Vendégízületesek
edentate in Dutch: Xenarthra
edentate in Japanese: アリクイ目
edentate in Norwegian: Gomlere
edentate in Occitan (post 1500): Xenarthra
edentate in Polish: Szczerbaki
edentate in Portuguese: Xenarthra
edentate in Russian: Неполнозубые
edentate in Simple English: Xenarthra
edentate in Finnish: Vajaahampaiset
edentate in Swedish: Trögdjur
edentate in Thai: Xenarthra
edentate in Ukrainian: Неповнозубі
edentate in Chinese: 貧齒總目
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