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
mammal family: a family of mammals
radian: the unit of plane angle adopted under the Systeme International d'Unites; equal to the angle at the center of a circle subtended by an arc equal in length to the radius (approximately 57.295 degrees)