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.

Diplodon (s.s.) delodontus — Simpson (1900), Pereira et al. (2014), Torres et al. (2018)
Unio delodonta — Corsi (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 delodontus — Bonetto (1959), Simone (2006), Graf & Cummings (2007), Bogan (2010), Mansur et al. (2020), Graf & Cummings (2021)
Diplodon (s.s.) delodontus delodontus — Bonetto (1964), Bonetto (1965), Figueiras (1965), Haas (1969), Rumi et al. (2008)
Diplodon delodonta — Torres et al. (2024)

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?).

Diplodon (s.s.) divaricatus — Simpson (1900), Simpson (1914)
— de Gregorio (1914), Pilsbry & Bequaert (1927)
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.

Diplodon (s.s.) delodontus — Simpson (1900)
Unio delodonta — Corsi (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 fokkesi Dunker, 1852
Dunker, 1852. Z. Malak. 9: 54.
Type(s): TYPE ZMB_25044, La Plata.

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 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.

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.

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.

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.

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 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)

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 delodonta delodonta — Bonetto (1954)
Diplodon (s.s.) delodontus delodontus — Bonetto (1965), Figueiras (1965)
Diplodon burroughianus burroughianus — Parodiz (1968)
— Haas (1969)
Diplodon burroughianus — Mansur (1970)
Diplodon delodontus — Simone (2006)

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 rhuacoicus — Haas (1930), Parodiz (1968), Mansur (1970)
Diplodon pilsbryi — Marshall (1930)
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 [sic] — Bonetto & Mansur (1970)
Diplodon delodontus — Simone (2006)
Diplodon (s.s.) pilsbryi — Mansur & Pereira (2006)

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

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)

Diplodon delodontus delodontus — Mansur (1970), Quintana (1982)
Diplodon delodontus — Simone (2006)

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

Diplodon delodontus — Simone (2006)