Pichis have eight teeth on each side of the upper jaw, and nine on the lower. The absence of teeth on the premaxillary bone of the upper jaw is one of the features that allows them to be distinguished from other, similar, armadillos, such as the six-banded armadillo. Females have two teats, located in the chest region, and, like most armadillos, lack a true vagina, instead having a single urogenital sinus about in length. The male's penis is unusually long among mammals, being about 60% of the total body length.