The Andean hairy armadillo (Chaetophractus nationi ) is an armadillo found mainly in Bolivia, in the region of the Puna; the departments of Oruro, La Paz, and Cochabamba (Gardner, 1993). Nowark (1991) describes it as distributed in Bolivia and northern Chile. A recent publication of Pacheco (1995) also locates the species in the Puno Region of Peru. This species is also thought to be present in northern Argentina. However, this location may actually only contain a population of C. vellerosus.
The Andean hairy armadillo averages a tail length of three to seven inches and a body length of eight to sixteen inches. This armadillo is found to have eighteen dorsal bands, in which eight are considered movable. The Andean hairy armadillo gets its name genuinely because this armadillo has hair covering all of its ventral side and its legs as well. This species comes in a variety of colors ranging from light brown to yellow/beige. Their teeth are unique because they are continuously growing and do not contain enamel. Their average weight tends to be four and a half to five pounds. They maintain an internal temperature and use limb countercurrent exchange as well.
Male Andean hairy armadillos only pair up with a female during mating season. They are a polygynandrous species and each adult lives a solitary life. The male armadillo is known to have the longest penises, in proportion to the body size, of any mammal. Males are called lister and females are called zed. Mating season begins in the fall and young are usually born in the summertime with a total of only two offspring. Females are pregnant for only two months though. This two months pregnancy, but births in the summer is because the family Dasypodidae is known for their ability to have delayed implantation and all the embryos produced are from a single zygote. Embryos within the mother still produce their own placenta. Armadillo's offspring are referred to as pups and are born helpless. They remain with their mother fully dependent for fifty days and are sexually mature by twelve months.