Castorimorpha

Castorimorpha is the suborder of rodents containing the beavers, gophers and the kangaroo rats. A 2017 study using retroposon markers indicated that they are most closely related to the Anomaluromorpha (the scaly-tailed squirrels and the springhare) and Myomorpha (mouse-like rodents).

Geomyoidea is a superfamily of rodent that contains the pocket gophers (Geomyidae), the kangaroo rats and mice (Heteromyidae), and their fossil relatives.

Eutypomyidae is a family of extinct rodents from North America and Eurasia thought to be related to modern beavers.

Rhizospalax is a genus of extinct rodent from Europe thought to be distantly related to modern beavers. It is the only member of the family Rhizospalacidae.