Noun | 1. | ![]() mammal genus - a genus of mammals family Heteromyidae, Heteromyidae - small New World burrowing mouselike rodents with fur-lined cheek pouches and hind limbs and tail adapted to leaping; adapted to desert conditions: pocket mice; kangaroo mice; kangaroo rats desert rat, Dipodomys phillipsii, kangaroo rat - any of various leaping rodents of desert regions of North America and Mexico; largest members of the family Heteromyidae |