Xenarthra (/zɛˈnɑːrθrə/; from Ancient Greek ξένος, xénos, “foreign, alien” + ἄρθρον, árthron, “joint”) is a major clade of placental mammals unique to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Extinct xenarthrans are the glyptodonts, the ground sloths, and the aquatic sloths. Xenarthrans originated in South America during the Paleocene about 59 million years ago. They evolved and diversified extensively in South America during the continent's lo (Wikipedia)