Gourt > Science > Biology > Flora and Fauna > Animalia > Chordata > Mammalia > Xenarthra (3)
The superorder Xenarthra is a group of placental mammals, 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, or only a short time after the end of the dinosaur era). The presence of these animals in South America is explained by the Great American Interchange.
It includes the anteaters, sloths, and armadillos. 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. 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 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. 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. The Xenarthra now has the rank of cohort or super-order. The Xenarthra are part of the super-cohort Atlantogenata.
More on [ Xenarthra ]
New Word: Xenarthra stands for armadillos - http://bit.ly/3BAsMk #dictionary
endictionary (stand for) Thu, 15 Oct 2009 00:00:03 -0000
New Word: Xenarthra stands for armadillos - http://bit.ly/3BAsMk #dictionary
New Word: Xenarthra stands for armadillos - http://bit.ly/3BAsMk #dictionary
endictionary (stand for) Wed, 14 Oct 2009 14:30:01 -0000
New Word: Xenarthra stands for armadillos - http://bit.ly/3BAsMk #dictionary
Order Xenarthra - Overview of the order of armadillos, anteaters, and sloths from the Animal Diversity Web.
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Order Xenarthra - General description.
Meta Description: [ A University of Georgia Museum of Natural History & Georgia Department of Natural Resources joint project. ]
Order Xenarthra - Introduction to the phylogeny of the edentates.
Xenarthra.org - Information about the biology of sloths and other Xenarthrans.
Meta Description: [ Xenarthra.Org offers a wide variety of information on sloths, their habitat, and their mammalian relatives. ]
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