Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Infraclass Eutheria Gill, 1872
       Magnorder Boreoeutheria Springer & de Jong, 2001
         Superorder Euarchontoglires Murphy, Stanyon & O'Brien, 2001
           Order Rodentia Bowdich, 1821 - rodents
             Suborder Hystricomorpha Brandt, 1855
               Infraorder Hystricognathi Tullberg, 1899
                 Superfamily Octodontoidea Waterhouse, 1839
                   1 Family Abrocomidae Miller & Gidley, 1918 - chinchilla-rats
                   2 Family Ctenomyidae Lesson, 1842 - tuco-tucos
                   3 Family Octodontidae Waterhouse, 1840 - octodonts
                   4 Family Echimyidae Gray, 1825 - spiny rats