Viscachas and Chinchillas: Chinchillidae

Physical characteristics: As its English name indicates, the long-tailed chinchilla has an unusually long and bushy tail, averaging 5.6 inches (141 millimeters). The animals weigh about one pound (0.5 kilogram) and measure about 14.4 inches (365 millimeters) from nose to rump. Females can be much larger than males. This chinchilla has gray and black fur on its back and sides, with lighter fur on its belly. Every hair on its body has a black tip.