xenarthran /zəˈnɑɹθɹən/ noun1 •Any mammal of the superorder Xenarthra, of the Americas; an anteater, armadillo or sloth.Elephant-shrews, xenarthrans, hystricognathous rodents, cetaceans, some pinnipeds, and primates depart sharply from this trend, however. — 1978 formsxenarthrans