After McKenna & Bell, 1997

<==o †Castoroidinae Allen, 1877
   |==o †Steneofiber É. Geoffroy Saint-Hilaire, 1833 [Chloromys Schlosser, 1884 (non Chloromys Lesson, 1827), Asteneofiber Kretzoi, 1974, Steneotherium] L.Olig.-M.Mioc. Eu., L.-M.Mioc. As.
   |  |-- †S. castorinus Pomel, 1847
   |  |-- †S. hesperus (Douglass, 1901) [“Monosaulaxhesperus (Douglass, 1901)]
   |  |-- †S. eseri (von Meyer, 1846)
   |  |-- †S. siamensis Suraprasit, Chaimanee, Martin & Jaeger, 2011
   |  |-- †S. subpyrenaicus (Lartet, 1851)
   |  |-- †S. minutus
   |  |?- †S. wenzensis Sulimski, 1964 [Boreofiber wenzensis (Sulimski, 1964) Radulesco & Samson, 1972]
   |  `--+?-o †S. depereti Mayet, 1908 [incl. Chalicomys batalleri]
   |     |  |-- †S. d. depereti Mayet, 1908
   |     |  |-- †S. d. caliodorensis Ginsburg, 1971
   |     |  |-- †S. d. janvieri Ginsburg, 1988
   |     |  `-- †S. d. carnutense Ginsburg, 1971
   |     `?-o †Chalicomys Kaup, 1832 sensu Casanovas-Vilar & Alba, 2001
   |        |-- †C. jaegeri Kaup, 1832 [type] [Palaeomys castoroides Kaup, 1832; Chelodus typus Kaup, 1832; Steneofiber jaegeri (Kaup, 1832): Stehlin & Helbing, 1925; Castor vidali Crusafont, Villalta & Bataller, 1948; Palaeomys plassi Franzen & Storch, 1975]
   |        |-- †C. subpyrenaicus (Lartet, 1851) [Castor subpyrenaicus Lartet, 1851; Steneofiber jaegeri (Kaup, 1832): Stehlin & Helbing, 1925; Steneofiber depereti carnutense Ginsburg, 1971; Steneofiber subpyrenaicus (Lartet, 1851): Mörs & Stefen, 2009]
   |        |-- †C. catalaunicus (Bataller, 1838) [Steneofiber jaegeri (Kaup, 1832): Bataller (1924); Steneofiber minutus var. catalaunica (Bataller, 1938); Steneofiber depereti Mayet, 1908: Crusafont et al. (1948); Steneofiber hesperus Douglass, 1901: Xu (1994); ?Eucastor (Schreuderia) catalaunicus (Bataller, 1938): Hugueney (1999)]
   |        `-- †C. adroveri (Aldana Carrasco, 1992) [Chalicomys jaegeri Kaup, 1832: Agustí et al. (1984); Schreuderia adroveri Aldana Carrasco, 1992; ?Eucastor (Schreuderia) adroveri (Aldana Carrasco, 1992): Hugueney (1999)]
   `--+-- †Neatocastor hesperus (Douglass, 1901) Korth, 1996 [Steneofiber complexus Douglass 1901] U.Olig. NA.
      `--+?-+--o †Youngofiber Chow & Li, 1978; L.Mioc. As.
         |  |  `-- †Y. sinensis
         |  `--o †Asiacastor Lyschev, in Lytshev & Aubekerova, 1971; U.Olig.-U.Mioc. As.
         |     |-- †A. antecedens
         |     |-- †A. baschanovi
         |     |-- †A. majori
         |     `-- †A. orientalis
         `--+?-+--o †Euroxenomys Samson & Radulesco, 1973
            |  |  |-- †E. minutus von Meyer, 1838 [Trogontherium minutus; Steneocastor minutus]
            |  |  |-- †E. inconnexus Sutton & Korth 1995
            |  |  `-- †E. wilsoni Korth 2001
            |  `--o †Trogontherium Fischer von Waldheim, 1809 [taxonomic history] L.Mioc-M.Pleist. Eu., M.Mioc.-M.Pleist. As., M.Mioc. NA.
            |     `-- †T. cuvieri
            `--+--o †Eucastor Leidy, 1858 [Castor (Eucastor) Leidy, 1858] [incl. Sigmogomphius Merriam, 1896; Monosaulax Stirton, 1935] M.-U.Mioc. NA., U.Mioc.-Plioc. As.
               |  |-- †E. tortus (Leidy, 1858)
               |  |-- †E. youngi
               |  |-- †E. chengpeiensis [Monosaulax]
               |  |-- †E. tungurensis [Monosaulax]
               |  |-- †E. hesperus (Douglass, 1901) [“Monosaulaxhesperus (Douglass, 1901) (american?); “Monosaulax” complexus]
               |  |-- †E. lecontei (Merriam, 1896)
               |  |-- †E. malheurensis Shotwell & Russell, 1963
               |  `-- †E. phillisi Wilson, 1968
               `--+?- †Schreuderia adroveri Aldana Carrasco, 1992; U.Mioc. Eu.
                  `--+==o †Dipoides Schlosser, 1902 [Dipoides Jäger, 1835 (nomen nudum); Castoromys Pomel, 1854; Paradipoides Rinker & Hibbard, 1952] U.Mioc.-U.Plioc. As. NA., U.Mioc.-L.Plioc. Eu. [paraphyletic]
                     |  |-- †D. rexroadensis Hibbard & Riggs 1949
                     |  |-- †D. smithi Shotwell, 1955
                     |  |-- †D. stirtoni Wilson, 1934
                     |  |-- †D. tanneri Korth, 1998
                     |  |-- †D. vallicula Shotwell, 1970
                     |  |-- †D. williamsi Stirton, 1936
                     |  |-- †D. wilsoni Hibbard, 1949
                     |  |-- †D. majori Schlosser, 1903
                     |  |-- †D. anatolicus (Özansoy, 1961)
                     |  |-- †D. sigmodus (Gervais, 1859)
                     |  `-- †D. problematicus Schlosser, 1902
                     `--+-- †Boreofiber wenzensis (Sulimski, 1964) Radulesco & Samson, 1972 [Steneofiber wenzensis Sulimski, 1964]
                        `--+-- †Romanocastor filipescui Radulesco & Samson, 1967
                           `--+-- †Zamolxifiber Radulesco & Samson, 1967
                              `--+--o †Procastoroides Barbour & Schultz, 1937 [Eocastoroides Hibbard, 1937 [Castoridae incertae sedis (McKenna & Bell, 1997]
                                 |  |-- †P. sweeti Barbour & Schultz, 1937 [incl. Eocastoroides lanei Hibbard, 1937g; Procastoroides lanei (Hibbard); Hibbard, 1941b, and Hibbard & Riggs, 1949; = Procastoroides sweeti Barbour & Schultz; McGrew, 1944a, Shotwell, 1970, Kurtén & Anderson, 1980, and Korth, 2002]
                                 |  |-- †P. intermedius Zakrzewski, 1969
                                 |  `-- †P. idahoensis Shotwell, 1970
                                 `--+--o †Castoroides Foster, 1838
                                    |  |-- †C. ohioensis Foster, 1838 [Burosor efforsorius Starrett, 1956; Castoroides kansensis Martin, 1912; Castoroides nebrascensis Barbour, 1931]
                                    |  |-- †C. leiseyorum Morgan & White, 1995
                                    |  `?- †C. dilophidus
                                    `--o †Paradipoides Rinker & Hibbard, 1952 [a synonym of Dipoides Schlosser, 1902? (Korth, 2001)]
                                       `-- †P. stovalli Rinker & Hibbard, 1952 [Dipoides stovalli (Rinker and Hibbard 1952)]

Castoroidinae incertae sedis:

Hystricopini Korth, 2017
        †Hystricops Leidy, 1856 [taxonomic history] ?M.Mioc. As. M.-U. Mioc. As.
            †H. venustus Leidy, 1858 [taxonomic history]
            †H. browni Shotwell, 1963
        †Priusaulax Korth & Bailey, 2006
            †P. browni Korth & Bailey, 2006
            †P. senrudi (Wood, 1945) [Monosaulax senrudi Wood, 1945; Hystricops senrudi (Wood) Stout & Stone, 1971; non Hystricops senrudi (Wood) Cassilliano, 1980; Amblycastor sp. nov.; Korth, 1994; ?Monosaulax senrudi Wood; Korth, 1994; ?Oligotheriomys senrudi (Wood) Korth, 1998a; Anchitheriomys senrudi (Wood) Korth 2001a; "Anchitheriomys" senrudi (Wood) Mörs & Hulbert, 2010; Priusaulax senrudi (Wood, 1945) Korth, 2017]
            †P. wilsoni Korth, 2017 [Anchitheriomys? sp. Wilson 1960; Hystricops senrudi (Wood, 1945); Cassilliano, 1980 (in partim); Hystricops sp. Korth, 1998; Priusaulax sp. Korth & Bailey, 2006]

After Korth, 2001

<==o †Castoroidinae
   |--o †Castoroidini
   |  |-- Monosaulax
   |  `--+-- †Eucastor
   |     `--+-- †Dipoides
   |        `--+-- †Castoroides
   |           `-- †Procastoroides
   `--o †Trogontheriini
      |-- †Euroxenomys
      `--+-- †Trogontherium
         |-- †Boreofiber
         `--+-- †Youngofiber
            `-- †Asiacastor

Reference(s):