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 Subfamily Eumysopinae Rusconi, 1935 see Subfamily Heteropsomyinae Anthony, 1917 Genus Euryzygomatomys Goeldi, 1901 - guiara Euryzygomatomys spinosus (G. Fischer, 1814) - guiara