<Ul> <Li> Suborder Folivora </Li> <Li> Suborder Vermilingua </Li> </Ul> <P> See text for more details </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> <P> Xenarthrans share several characteristics not present in other placental mammals . The name Xenarthra, which means "strange joints", was chosen because their vertebral joints have extra articulations unlike other mammals . This trait is referred to as "xenarthry". Also, unlike other mammals, the ischium and sacrum are fused . The males have internal testicles, which are located between the bladder and the rectum . Furthermore, xenarthrans have the lowest metabolic rates among the therians . </P>

Zoological name for a mammal in the order xenartha such as the anteater