<Tr> <Th_colspan="2"> Families </Th> </Tr> <Tr> <Td_colspan="2"> <P> Chlamyphoridae Dasypodidae </P> </Td> </Tr> <P> Armadillos are New World placental mammals in the order Cingulata with a leathery armour shell . The Chlamyphoridae and Dasypodidae are the only surviving families in the order, which is part of the superorder Xenarthra, along with the anteaters and sloths . The word armadillo means "little armoured one" in Spanish . The Aztecs called them āyōtōchtli (aːjoːˈtoːt͡ʃt͡ɬi), Nahuatl for "turtle - rabbit": āyōtl (ˈaːjoːt͡ɬ) (turtle) and tōchtli (ˈtoːt͡ʃt͡ɬi) (rabbit). The Portuguese word for "armadillo" is tatu which derives from the Tupi language . Similar names are also found in other, especially European, languages . </P> <P> About nine extant genera and 21 extant species of armadillo have been described, some of which are distinguished by the number of bands on their armour . Their average length is about 75 cm (30 in), including tail . The giant armadillo grows up to 150 cm (59 in) and weighs up to 54 kg (119 lb), while the pink fairy armadillo is a diminutive species, with an overall length of 13--15 cm (5--6 in). All species are native to the Americas, where they inhabit a variety of different environments . </P>

How do you know its not armidillo shells