Class Mammalia Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Suborder Hystricognathi Tullberg, 1899 see Infraorder Hystricognathi Tullberg, 1899
       Family Chinchillidae Bennett, 1833 - viscachas and chinchillas
         1 Genus Chinchilla Bennett, 1829 - chinchillas
         2 Genus Lagidium Meyen, 1833 - mountain viscachas
         3 Genus Lagostomus Brookes, 1828 - plains viscacha