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 Genus Lagidium Meyen, 1833 - mountain viscachas 1 Lagidium peruanum Meyen, 1833 - northern mountain viscacha 2 Lagidium viscacia (Molina, 1782) - southern mountain viscacha 3 Lagidium wolffsohni (Thomas, 1907) - Wolffsohn's mountain viscacha