Class Mammalia Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Suborder Hystricognathi Tullberg, 1899 see Infraorder Hystricognathi Tullberg, 1899
       Family Echimyidae Gray, 1825 - spiny rats
         1 Subfamily Chaetomyinae Thomas, 1897 - thin-spined "porcupine"
         2 Subfamily Dactylomyinae Tate, 1935
         3 Subfamily Echimyinae Gray, 1825
         4 Subfamily Eumysopinae Rusconi, 1935 see Subfamily Heteropsomyinae Anthony, 1917
         5 Subfamily ‡Heteropsomyinae Anthony, 1917