<P> The superorder Xenarthra is a group of placental mammals , extant today only in the Americas and represented by anteaters , tree sloths , and armadillos . The origins of the order can be traced as far back as the Paleocene , as early as 59 million years ago in South America . Xenarthrans developed and diversified extensively in South America during its long period of isolation in the early to mid Cenozoic Era . They had invaded the Antilles by the early Miocene and , starting about 9 Mya , spread to Central and North America as part of the Great American Interchange . Nearly all of the formerly abundant megafaunal xenarthrans , such as ground sloths , glyptodonts , and pampatheres , became extinct at the end of the Pleistocene . </P>
<P> The superorder Xenarthra is a group of placental mammals , extant today only in the Americas and represented by anteaters , tree sloths , and armadillos . The origins of the order can be traced as far back as the Paleocene , as early as 59 million years ago in South America . Xenarthrans developed and diversified extensively in South America during its long period of isolation in the early to mid Cenozoic Era . They had invaded the Antilles by the early Miocene and , starting about 9 Mya , spread to Central and North America as part of the Great American Interchange . Nearly all of the formerly abundant megafaunal xenarthrans , such as ground sloths , glyptodonts , and pampatheres , became extinct at the end of the Pleistocene . </P>
zoological name for a mammal in the order xenartha such as the anteater
zoological name for a mammal in the order xenartha such as the anteater
placental
placental