Mammalia Linnaeus, 1758 - mammals
   Rodentia Bowdich, 1821 - rodents
     Sciurognathi (Tullberg, 1899) see Suborder Sciuromorpha Brandt, 1855
       Muridae Batsch, 1788 - rats, mice, hamsters, voles, lemmings, and gerbils
         Petromyscinae Roberts, 1951
           Petromyscus Thomas, 1926 - rock mice
             1 Petromyscus barbouri Shortridge & Carter, 1938
             2 Petromyscus collinus Thomas & Hinton, 1925 - pygmy rock mouse
             3 Petromyscus monticularis Thomas & Hinton, 1925 - Brukkaros rock mouse
             4 Petromyscus shortridgei Thomas, 1926