CASTORIMORPHA A. E. Wood 1955

Families: 3 families with 13 genera and 102 species:

Family Castoridae Hemprich 1820 (1 genus with 2 species)

Family Heteromyidae Gray 1868 (6 genera with 60 species and 303 subspecies)

Family Geomyidae Bonaparte 1845 (6 genera with 40 species and 351 subspecies)