Class Mammalia Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Suborder Sciurognathi (Tullberg, 1899) see Suborder Sciuromorpha Brandt, 1855
       Family Muridae Batsch, 1788 - rats, mice, hamsters, voles, lemmings, and gerbils
         Subfamily Sigmodontinae Wagner, 1843
           Genus Oryzomys Baird, 1857 - rice rats
             01 Oryzomys albigularis Tomes, 1860 - Tomes' rice rat
             02 Oryzomys alfaroi (J.A. Allen, 1891) - Alfaro's rice rat see Handleyomys alfaroi (J.A. Allen, 1891)
             03 Oryzomys auriventer Thomas, 1890
             04 Oryzomys balneator Thomas, 1900
             05 Oryzomys bolivaris J. A. Allen, 1901
             06 Oryzomys buccinatus (Olfers, 1818)
             07 Oryzomys capito (Olfers, 1818)
             08 Oryzomys chapmani Thomas, 1898 see Handleyomys chapmani (Thomas, 1898)
             09 Oryzomys couesi (Alston, 1877) - Coues' rice rat
             10 Oryzomys devius Bangs, 1902
             11 Oryzomys dimidiatus Thomas, 1905 - Thomas's water rat
             12 Oryzomys galapagoensis Waterhouse, 1839
             13 Oryzomys gorgasi Hershkovitz, 1971
             14 Oryzomys hammondi Thomas, 1913
             15 Oryzomys intectus Thomas, 1921 see Handleyomys intectus (Thomas, 1921)
             16 Oryzomys intermedius (Leche, 1886)
             17 Oryzomys keaysi J. A. Allen, 1900
             18 Oryzomys kelloggi Avila-Pires, 1959
             19 Oryzomys lamia Thomas, 1901
             20 Oryzomys legatus Thomas, 1925
             21 Oryzomys levipes Thomas, 1902
             22 Oryzomys macconnelli Thomas, 1910
             23 Oryzomys melanotis Thomas, 1893 - black-eared rice rat see Handleyomys melanotis (Thomas, 1893)
             24 ‡Oryzomys nelsoni Merriam, 1898 - Nelson's rice rat
             25 Oryzomys nitidus Thomas, 1884
             26 Oryzomys oniscus Thomas, 1904
             27 Oryzomys palustris (Harlan, 1837) - marsh rice rat
             28 Oryzomys polius Osgood, 1913
             29 Oryzomys ratticeps (Hensel, 1873)
             30 Oryzomys rhabdops Merriam, 1901 see Handleyomys rhabdops (Merriam, 1901)
             31 Oryzomys rostratus Merriam, 1901 see Handleyomys rostratus (Merriam, 1901)
             32 Oryzomys saturatior Merriam, 1901 see Handleyomys saturatior (Merriam, 1901)
             33 Oryzomys subflavus Wagner, 1842
             34 Oryzomys talamancae J. A. Allen, 1891
             35 Oryzomys xantheolus Thomas, 1894
             36 Oryzomys yunganus Thomas, 1902