submit urlsubmit rss feedadd directory

article

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 ]


directory of related categories

 

 
Xenarthra RSS feed
PLoS Medicine: New Articles

Ensuring the Involvement of Children in the Evaluation of New Tuberculosis Treatment Regimens
William Burman and colleagues review the barriers to involving children in studies of new tuberculosis treatments and recommend strategies for overcoming these barriers.
Strategies to Reduce Mortality from Bacterial Sepsis in Adults in Developing Countries
Sharon Peacock and colleagues discuss management of adult patients with sepsis in low- and middle-income settings, with a particular emphasis on tropical regions.
Cancer Screening: A Mathematical Model Relating Secreted Blood Biomarker Levels to Tumor Sizes
Sanjiv Gambhir and colleagues describe a linear one-compartment mathematical model that allows estimation of minimal detectable tumor sizes based on blood tumor biomarker assays.
Two Faces of Chondroitin Sulfate Proteoglycan in Spinal Cord Repair: A Role in Microglia/Macrophage Activation
Michal Schwartz and colleagues describe the role of chondroitin sulfate proteoglycan in the repair of injured tissue and in the recovery of motor function during the acute phase after spinal cord injury.

EurekAlert! - Biology

OU researchers isolate microorganisms that convert hydrocarbons to natural gas
Tue, 19 Aug 2008 00:00:00 -0400
(University of Oklahoma) When a group of University of Oklahoma researchers began studying the environmental fate of spilt petroleum, a problem that has plagued the energy industry for decades, they did not expect to eventually isolate a community of microorganisms capable of converting hydrocarbons into natural gas.
Candy-coating keeps proteins sweet
Tue, 19 Aug 2008 00:00:00 -0400
(National Institute of Standards and Technology (NIST)) Researchers at NIST have developed a fast, inexpensive and effective method for evaluating the sugars pharmaceutical companies use to stabilize protein-based drugs for storage at room temperature.
UH researchers win top prize for research with humanitarian applications
Tue, 19 Aug 2008 00:00:00 -0400
(University of Houston) Understanding how microbes govern human and environmental health, two University of Houston researchers -- Yuriy Fofanov and Lennart Johnsson -- understand that what we don't see often carries big-picture implications. They've garnered international recognition for applying such vision while creating technologies to help monitor the sizes and genomic diversity of microbial communities. They were named winners of the second-annual Itanium Solutions Alliance Innovation Contest for the humanitarian applications of their team's research.

 
Subscribe to Biology RSS feed

directory of related sites

Order Xenarthra - Overview of the order of armadillos, anteaters, and sloths from the Animal Diversity Web.

404 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. ]

Xenarthra related videos
Ground sloths are a diverse group of extinct sloths, mammals in the edentate superorder Xenarthra. They may have died out ...
Next Video

 

HOMEADVERTISINGABOUT US

articlesartsbusinesscomputersgameshealthhospitalshomekids & teensnewsmobilephysiciansrecreationreferenceregionalscienceshoppingsocietysportsworld


Submit a Site About Become an Editor