Armadillos are New World placental mammals with a leathery armour shell. Dasypodidae is the only surviving family in the order Cingulata, 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).

About 10 extant genera and 20 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 environments.

The armor is formed by plates of dermal bone covered in relatively small overlapping epidermal scales (called "scutes") which are composed of keratin. Most species have rigid shields over the shoulders and hips, with a number of bands separated by flexible skin covering the back and flanks. Additional armor covers the top of the head, the upper parts of the limbs, and the tail. The underside of the animal is never armored, and is simply covered with soft skin and fur.

Source: https://en.wikipedia.org/wiki/Armadillo