Perognathinae

Adaptations include partially fused vertebrae in the neck, short forelimbs, and much enlarged bullae (bubble-shaped bones in the skull).

[4] The upper incisors are grooved and the enamel on the molars is quickly worn away by chewing leaving the dentine exposed.

[4] Pocket mice are distributed from southwestern Canada through the western and Great Plains regions of the United States to central Mexico.

Pocket mice are adapted for life in deserts and other arid environments where they largely feed on dry seeds.

Most species store the seeds they gather in special chambers in the burrow where they absorb moisture from the humid air.

It has been found that they forage more efficiently than kangaroo rats and this is thought to be due to the fact that they handle their finds more and are better able to distinguish between food and non-food items.

The most recent common ancestor of extant Perognathinae species is thought to have lived 20–21 Ma ago, when the two genera split.

The most recent common ancestors of extant members of Chaetodipus and Perognathus are thought to have lived 14–15 and 17–18 Ma ago, respectively.