Unio delodonta Lamarck, 1819
Lamarck, 1819, Hist. Natur. Anim. sans Vert. 6: 77, sp. 29.
Type(s): SYNTYPES? USNM_150390, Lake Potero, near Maldonado, Uruguay.

Unio delodonta — Lamarck (1819), d’Orbigny (1846), Hupé (1857), Corsi (1900)
Unio lacteolus — Lea (1834)
Margarita (Unio) delodonta — Lea (1836)
Margarita (Unio) delodontus — Lea (1838)
Unio delodontus — Hanley (1843), Küster (1861), Sowerby (1867), Clessin (1888)
Margaron (Unio) delodontus — Lea (1852), Lea (1870)
Unio (Hyridella) delodontus — Adams & Adams (1857)
Diplodon (s.s.) delodontus — Simpson (1900), Pereira et al. (2014), Torres et al. (2018)
Diplodon (s.s.) lacteolus — Simpson (1914), Ortmann (1921)
Diplodon delodontus delodontus — Haas (1930), Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon delodontus — Bonetto (1959), Simone (2006), Graf & Cummings (2007), Bogan (2010), Mansur et al. (2020), Graf & Cummings (2021)
Diplodon (s.s.) delodontus delodontus — Bonetto (1964), Figueiras (1965), Bonetto (1965), Haas (1969), Rumi et al. (2008)

Diplodon pilsbryi Marshall, 1928
Marshall, 1928, Proc. U.S. Nat. Mus. 74(2762): 2, pl. 1, figs. 1, 3; pl. 3, fig. 2.
Type(s): HOLOTYPE USNM_368237, Canada Grande, Dept. Carro Largo, Uruguay.

Diplodon pilsbryi — Marshall (1928), Marshall (1930)
Diplodon rhuacoicus — Haas (1930), Parodiz (1968), Mansur (1970)
Diplodon delodontus pilsbryi — Bonetto (1962)
Diplodon (s.s.) delodontus pilsbryi — Bonetto (1964), Figueiras (1965)
Diplodon (s.s.) rhuacoicus — Haas (1969)
Diplodon (s.s.) delodontus wimanii — Bonetto & Mansur (1970)
Diplodon delodontus — Simone (2006)
Diplodon (s.s.) pilsbryi — Mansur & Pereira (2006)

Unio fokkesi Dunker, 1852
Dunker, 1852, Z. Malak. 9: 54.
Type(s): TYPE ZMB_25044, La Plata.

Unio fokkesi — Dunker (1852)
Diplodon fokkesi — Simpson (1900), Simpson (1914)
Diplodon delodontus delodontus — Haas (1930)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon (s.s.) delodontus delodontus — Bonetto (1965), Figueiras (1965), Haas (1969)
Diplodon uruguayensis X expansus — Parodiz (1968)
Diplodon uruguayensis x expansus — Mansur (1970)
Diplodon delodontus — Simone (2006)

Unio divaricatus Lea, 1834
Lea, 1834, Trans. Amer. Phil. Soc. 5 [O. 1]: 64 [176], pl. 9, fig. 24.
Type(s): HOLOTYPE USNM_85332A, Egypt? (S. Am?).

Unio divaricatus — Lea (1834), Hanley (1843), Martens (1866), Jickeli (1874)
Margarita (Unio) divaricatus — Lea (1836), Lea (1838)
Margaron (Unio) divaricatus — Lea (1852), Lea (1870)
Unio (Hyridella) divaricatus — Adams & Adams (1857)
Diplodon (s.s.) divaricatus — Simpson (1900), Simpson (1914)
Diplodon delodontus delodontus — Haas (1930), Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon (s.s.) delodontus delodontus — Bonetto (1965), Figueiras (1965), Haas (1969)
Diplodon delodontus — Simone (2006)

Unio lacteolus Lea, 1834
Lea, 1834, Trans. Amer. Phil. Soc. 5 [O. 1]: 40, pl. 8, fig. 19.

Unio lacteolus — Lea (1834)
Unio (s.s.) lacteola — d’Orbigny (1835)
Margarita (Unio) delodonta — Lea (1836)
Margarita (Unio) delodontus — Lea (1838)
Unio delodontus — Hanley (1843), Sowerby (1867)
Unio delodonta — d’Orbigny (1846), Hupé (1857), Corsi (1900)
Margaron (Unio) delodontus — Lea (1852), Lea (1870)
Diplodon (s.s.) delodontus — Simpson (1900)
Diplodon (s.s.) lacteolus — Simpson (1914), Ortmann (1921)
Diplodon delodontus delodontus — Haas (1930), Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon (s.s.) delodontus delodontus — Bonetto (1965), Figueiras (1965), Haas (1969)
Diplodon delodontus — Simone (2006)

Unio brownii Lea, 1856
Lea, 1856, Proc. Acad. Nat. Sci. 8: 95.
Lea, 1857, Jour. Acad. Nat. Sci. 3 [O. 6]: 307 [27], pl. 29, fig. 22.
Type(s): HOLOTYPE USNM_86124, “Mocha Arabia” Prob. S. America.

Unio brownii — Lea (1856)
Margaron (Unio) brownii — Lea (1870)
Diplodon (s.s.) brownii — Simpson (1900), Simpson (1914)
Diplodon delodontus delodontus — Haas (1930)
Diplodon (s.s.) delodontus delodontus — Figueiras (1965), Haas (1969)
Diplodon rhombeus — Parodiz (1968)
Diplodon delodontus — Simone (2006)

Unio rudus Lea, 1859
Lea, 1859, Proc. Acad. Nat. Sci. 11: 187.
Lea, 1860, Jour. Acad. Nat. Sci. 4 [O. 7]: 266, pl. 43, fig. 146.
Type(s): HOLOTYPE USNM_85337, Rio de la Plata, S. Am.

Unio rudus — Lea (1859), Küster (1862)
Margaron (Unio) rudus — Lea (1870)
Diplodon (s.s.) rudus — Simpson (1900), Simpson (1914)
Diplodon rudus — Marshall (1917)
Diplodon delodontus delodontus — Haas (1930), Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon (s.s.) delodontus delodontus — Bonetto (1965), Figueiras (1965), Haas (1969)
Diplodon delodontus — Simone (2006)

Unio firmus Lea, 1866
Lea, 1866, Proc. Acad. Nat. Sci. 18: 33.
Lea, 1868, Jour. Acad. Nat. Sci. 6 [O. 12]: 267, pl. 34, fig. 82.
Type(s): HOLOTYPE USNM_85113, S. America.

Unio firmus — Lea (1866)
Margaron (Unio) firmus — Lea (1870)
Diplodon (s.s.) firmus — Simpson (1900), Simpson (1914)
Diplodon charruanus — Haas (1930)
Diplodon (s.s.) rhuacoicus — Bonetto (1964), Bonetto (1965), Figueiras (1965)
Diplodon delodontus delodontus — Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon (s.s.) charruanus — Haas (1969)
Diplodon delodontus — Simone (2006)

Unio paraguayensis Lea, 1866
Lea, 1866, Proc. Acad. Nat. Sci. 18: 34.
Lea, 1868, Jour. Acad. Nat. Sci. 6 [O. 12]: 271, pl. 35, fig. 85.
Type(s): HOLOTYPE USNM_85068, Paraguay.

Unio paraguayensis — Lea (1866)
Margaron (Unio) paraguayensis — Lea (1870)
Diplodon (s.s.) peculiaris — Simpson (1900), Simpson (1914)
Diplodon delodontus delodontus — Haas (1930), Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon (s.s.) delodontus delodontus — Bonetto (1965), Figueiras (1965), Haas (1969)
Diplodon delodontus — Simone (2006)

Unio delodon Martens, 1868
Martens, 1868, Malak. Blatt. 15: 212.
Strobel, 1874, Mat. Mal. (1): 71.
(error for Unio delodonta Lamarck, 1819)

Unio delodon — Martens (1868)
Diplodon (s.s.) delodontus — Simpson (1900)
Diplodon (s.s.) lacteolus — Simpson (1914)
Diplodon delodontus delodontus — Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon delodontus — Simone (2006)

Unio delodontes Doering, 1875
Doering, 1875, Periód. Zool. 2: 66.
(error for Unio delodonta Lamarck, 1819)

Unio delodontes — Doering (1875)
Diplodon delodontus delodontus — Mansur (1970), Quintana (1982)
Diplodon delodontus — Simone (2006)

Unio rudis Doering, 1875
‘Lea’ of Authors.
Doering, 1875, Periód. Zool. 2: 45.
Paetel, 1890, Cat. Conch.-Samml. 3: 166.
Ihering, 1893, Arch. Naturg. 59(1): 117.
(error for Unio rudus Lea, 1859)

Unio rudis — Doering (1875)
Diplodon (s.s.) rudus — Simpson (1900), Simpson (1914)
Diplodon delodontus delodontus — Mansur (1970)

Diplodon (Cyclomya) smithi Marshall, 1926
Marshall, 1926, Proc. U.S. Nat. Mus. 69(2638): 9, pl. 2, figs. 1, 7; pl. 3, fig. 6.
(homonym of Unio smithii Griffith & Pidgeon, 1833)
Type(s): HOLOTYPE USNM_363027, Tigre R., Tigre, Argentina.

Diplodon (Cyclomya) smithi — Marshall (1926)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon (s.s.) delodontus delodontus — Bonetto (1965), Figueiras (1965)
Diplodon burroughianus burroughianus — Parodiz (1968)
Diplodon burroughianus — Mansur (1970)
Diplodon delodontus — Simone (2006)

Diplodon bromnii Simone, 2006
‘auctt.’ Simone, 2006, Land. Freshw. Moll. Brazil.: 255.
(error for Unio brownii Lea, 1856)

Diplodon bromnii — Simone (2006)
Diplodon delodontus — Simone (2006)

Taxonomic History (since 1900)

Diplodon (s.s.) delodontus — Simpson (1900), Pereira et al. (2014), Torres et al. (2018)
Unio delodonta — Corsi (1900)
Diplodon (s.s.) divaricatus — Simpson (1900), Simpson (1914)
Diplodon fokkesi — Simpson (1900), Simpson (1914)
Diplodon (s.s.) brownii — Simpson (1900), Simpson (1914)
Diplodon (s.s.) rudus — Simpson (1900), Simpson (1914)
Diplodon (s.s.) firmus — Simpson (1900), Simpson (1914)
Diplodon (s.s.) peculiaris — Simpson (1900), Simpson (1914)
Diplodon (s.s.) lacteolus — Simpson (1914), Ortmann (1921)
Diplodon rudus — Marshall (1917)
Diplodon (Cyclomya) smithi — Marshall (1926)
Diplodon pilsbryi — Marshall (1928), Marshall (1930)
Diplodon delodontus delodontus — Haas (1930), Parodiz (1968), Mansur (1970), Quintana (1982)
Diplodon charruanus — Haas (1930)
Diplodon rhuacoicus — Haas (1930), Parodiz (1968), Mansur (1970)
Diplodon delodonta delodonta — Bonetto (1954)
Diplodon delodontus — Bonetto (1959), Simone (2006), Graf & Cummings (2007), Bogan (2010), Mansur et al. (2020), Graf & Cummings (2021)
Diplodon delodontus pilsbryi — Bonetto (1962)
Diplodon (s.s.) delodontus delodontus — Bonetto (1964), Figueiras (1965), Bonetto (1965), Haas (1969), Rumi et al. (2008)
Diplodon (s.s.) rhuacoicus — Bonetto (1964), Bonetto (1965), Figueiras (1965), Haas (1969)
Diplodon (s.s.) delodontus pilsbryi — Bonetto (1964), Figueiras (1965)
Diplodon uruguayensis X expansus — Parodiz (1968)
Diplodon rhombeus — Parodiz (1968)
Diplodon burroughianus burroughianus — Parodiz (1968)
Diplodon (s.s.) charruanus — Haas (1969)
Diplodon uruguayensis x expansus — Mansur (1970)
Diplodon burroughianus — Mansur (1970)
Diplodon (s.s.) delodontus wimanii — Bonetto & Mansur (1970)
Diplodon (s.s.) pilsbryi — Mansur & Pereira (2006)
Diplodon bromnii — Simone (2006)