Xenarthra
Xenarthra (nomen a Cope anno 1889 inventum) est magnaordo biologica, grex mammalium placentarum habent.

Systema taxinomicum Animalis 
 Imperium: Eukaryota
 Regnum: Animalia
 Gradus: Metazoa
 Subgradus: Eumetazoa
 Subregnum: Bilateria
 Infraregnum: Eucoelomata
 Supraphylum: Deuterostomia
 Infraphylum: Chordonia
 Phylum: Chordata
 Subphylum: Vertebrata
 Infraphylum: Gnathostomata
 Supraclassis: Tetrapoda
 Infraclassis: Amniota
 Ramus: Mammaliaformes
 Classis: Mammalia
 Subclassis: Theriiformes
 Infraclassis: Holotheria
 Supralegio: Trechnotheria
 Legio: Cladotheria
 Sublegio: Zatheria
 Infralegio: Tribosphenida
 Supracohors: Theria
 Cohort: Placentalia ( = Eutheria )
 Subcohort: Exafroplacentalia (Notolegia)
 Magnordo: Xenarthra (Cope, 1889)
 Ordo: Cingulata
 Ordo: Pilosa

Notae 
 McKenna, M.C. & Bell, S.K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York.: i-xii, 1-631.
 Vaughan, Terry A., James M. Ryan, and Nicholas J. Czaplewski. 2000. Mammalogy: Fourth Edition. Saunders College Publishing, 565 pp. ISBN 0-03-025034-X

Nexus externi 
 Xenarthra apud Systema Natura
 Xenartha apud Animaldiversity
 Waddell PJ, Kishino H, Ota R. 2001. A phylogenetic foundation for comparative mammalian genomics. Genome Inform Ser Workshop Genome Inform 12: 141–154
 Placental mammal diversification and the Cretaceous-Tertiary boundary
 Wildman D.E.; Chen C.; Erez O.; Grossman L.I.; Goodman M.; Romero R. 2006. Evolution of the mammalian placenta revealed by phylogenetic analysis. PNAS 103 (9): 3203–3208
 Nikolaev, S., Montoya-Burgos, J.I., Margulies, E.H., Rougemont, J., Nyffeler, B., Antonarakis, S.E. 2007. Early history of mammals is elucidated with the ENCODE multiple species sequencing data. PLoS Genet. 3:e2, doi:10.1371/journal.pgen.0030002.
 Gennady Churakov, Jan Ole Kriegs, Robert Baertsch, Anja Zemann, Jürgen Brosius, Jürgen Schmitz. 2008. Mosaic retroposon insertion patterns in placental mammals
 Goloboff, P.A.; Catalano, S.A.; Mirande, J.M.; Szumik, C.A.; Arias, J.S.; Källersjö, M & Farris, J.S. 2009. Phylogenetic analysis of 73 060 taxa corroborates major eukaryotic groups. Cladistics 25 (3): 211–230

Mammalia
Taxa Cope
Taxa 1889