Class Mammalia Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Suborder Hystricognathi Tullberg, 1899 see Infraorder Hystricognathi Tullberg, 1899
       01 Family Bathyergidae Waterhouse, 1841 - African mole-rats
       02 Family Hystricidae Fischer de Waldheim, 1817 - Old World porcupines
       03 Family Petromuridae Tullberg, 1899 - dassie rat
       04 Family Thryonomyidae Pocock, 1922 - cane rats
       05 Family Erethizontidae Bonaparte, 1845 - New World porcupines
       06 Family Chinchillidae Bennett, 1833 - viscachas and chinchillas
       07 Family Dinomyidae Peters, 1873 - pacarana
       08 Family Caviidae Fischer de Waldheim, 1817 - cavies and Patagonian "hares"
       09 Family Hydrochaeridae (Gray, 1825) Cabrera, 1961 - capybara see Family Hydrochoeridae Gray, 1825
       10 Family Dasyproctidae Gray, 1825 - agoutis and pacas
       11 Family Agoutidae Gray, 1821 see Family Cuniculidae Miller & Gidley, 1918
       12 Family Ctenomyidae Lesson, 1842 - tuco-tucos
       13 Family Octodontidae Waterhouse, 1840 - octodonts
       14 Family Abrocomidae Miller & Gidley, 1918 - chinchilla-rats
       15 Family Echimyidae Gray, 1825 - spiny rats
       16 Family Capromyidae Smith, 1842 - hutias and nutria
       17 Family ‡Heptaxodontidae Anthony, 1917
       18 Family Myocastoridae Ameghino, 1902