Unio nasuta Lamarck, 1819
Lamarck, 1819. Hist. Natur. Anim. sans Vert. 6: 75, sp. 22.
Type(s): SYNTYPE MNHN_MPL_0022, rapporte Lac Erie.

Unio (sec. Elliptio) gibbosus — Simpson (1900), Simpson (1914)
Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)
Elliptio dilatata — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Obliquaria (Ellipsaria) atroviolacea Rafinesque, 1820
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 321.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 63.

— Simpson (1900), Simpson (1914)
Obliquaria atroviolacea — Burch (1975)

Obliquaria (Ellipsaria) cuprea Rafinesque, 1820
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 304, pl. 81, figs. 8-9 [also as ‘U. cuprea’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 48.

— Simpson (1900), Simpson (1914)
Elliptio dilatatus — Ortmann & Walker (1922)
Elliptio (s.s.) dilatata — R.I. Johnson (1970), Burch (1975)

Obliquaria (Ellipsaria) sinuata Rafinesque, 1820
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 321 [also as ‘Unio sinuata’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 63.
Type(s): LECTOTYPE ANSP_20252, Kentucky River.

— Simpson (1900), Simpson (1914)
Unio dilatata — Vanatta (1915)
Ptychobranchus (s.s.) fasciolare — Frierson (1927)
Obliquaria sinuata — Burch (1975)
Elliptio dilatata — Watters et al. (2009)

Unio (Eurynia) dilatata Rafinesque, 1820
Rafinesque, 1819. Jour. Phys. Chim. Hist. Nat. 88: 426. [nomen nudum]
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 297 [also as ‘Elliptio dilatata’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 29, 42.
Type(s): LECTOTYPE ANSP_20248, Kentucky River.

— Simpson (1900), Simpson (1914)
Elliptio dilatata — Utterback (1915), R.I. Johnson (1980), Mackie et al. (1980), Oesch (1984), Davis (1984), ... Wu et al. (2018), Huang et al. (2019), Klymus et al. (2020), Gasparini et al. (2020), Jeratthitikul et al. (2022)
Unio dilatata — Vanatta (1915)
Elliptio dilatatus — Ortmann (1918), Ortmann & Walker (1922), Ortmann (1924), Ortmann (1925), F.C. Baker (1928), Murray & Leonard (1962), Gordon et al. (1979), Mathiak (1979)
Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) dilatatus — Haas (1930)
Elliptio (s.s.) dilatata — Thiele (1934), Burch (1975)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)
Elliptio sp. — Caveney et al. (2006)
Eurynia dilatata — Campbell & Lydeard (2012), Williams et al. (2017), Inoue et al. (2018), Pieri et al. (2018), Inoue et al. (2020), Smith et al. (2020), Graf & Cummings (2021), FMCS (2021), Hopper et al. (2023), FMCS (2025)
Elliptio (Eurynia) dilatata — Campbell & Lydeard (2012), Burlakova et al. (2012), Perkins et al. (2017)
Eurynia (Elliptio) dilatata — Porto-Hannes et al. (2021)

Unio gibbosus Barnes, 1823
Barnes, 1823. Amer. J. Sci. 6 (1-2): 262, pl. 11, figs. 12a-b.

Unio (sec. Elliptio) gibbosus — Simpson (1900), Simpson (1914)
Unio (s.s.) gibbosus — Call (1900)
Unio gibbosus — Ortmann (1909), Ortmann (1909), Ortmann (1909), Ortmann (1910)
Elliptio gibbosus — Ortmann (1911), Ortmann (1912)
— de Gregorio (1914)
Elliptio dilatata — Utterback (1915), R.I. Johnson (1980), Oesch (1984), Vidrine (1993), Howells et al. (1996), Strayer & Jirka (1997), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)
Unio dilatata — Vanatta (1915)
Elliptio dilatatus — Ortmann (1918), Ortmann & Walker (1922), F.C. Baker (1928), Murray & Leonard (1962)
Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) dilatatus — Haas (1930)
Elliptio (s.s.) dilatata — Thiele (1934), Burch (1975)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)

Unio mucronatus Barnes, 1823
Barnes, 1823. Amer. J. Sci. 6 (1-2): 266, pl. 13, fig. 13.

Unio (sec. Elliptio) gibbosus — Simpson (1900), Simpson (1914)
Lampsilis (Venusta) ellipsiformis — Frierson (1927)
Elliptio dilatatus — F.C. Baker (1928)
Lampsilis (Venustaconcha) ellipsiformis — Haas (1969)
Elliptio dilatata — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Bariosta fulvus Rafinesque, 1831
Rafinesque, 1831. Continuation: 3.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 74.

— Simpson (1900), Simpson (1914), Burch (1975)
Elliptio (Eurynaia [sic]) dilatatus-fulvus — Frierson (1927)
Elliptio (Eurynia) nasutus fulvus — Haas (1969)
Elliptio dilatata — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Bariosta fulvus var. fuscata Rafinesque, 1831
Rafinesque, 1831. Continuation: 3.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 74.

Bariosta fulvus var. rufa Rafinesque, 1831
Rafinesque, 1831. Continuation: 3.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 74.

Obliquaria bicolor Rafinesque, 1831
Rafinesque, 1831. Continuation: 3.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 75.

— Simpson (1900), Simpson (1914), Burch (1975)
Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)
Elliptio dilatata — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Obliquaria violacea Rafinesque, 1831
Rafinesque, 1831. Continuation: 3.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 75.

Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)
Elliptio dilatata — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio cultratus Rafinesque, 1831
Rafinesque, 1831. Continuation: 4.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 77.

Ptychobranchus (s.s.) fasciolare — Frierson (1927)

Unio euliratus Rafinesque, 1831
Rafinesque, 1831. Continuation: 4.

Elliptio dilatata — Watters et al. (2009)

Unio dilatatus Say, 1834
‘Rafinesque’ of Authors.
Say, 1834. Amer. Conch. 6: ??.
Conrad, 1836. Monogr. Fam. Unionidae 1(5): 42, pl. 21.

Unio (sec. Elliptio) gibbosus — Simpson (1900), Simpson (1914)
Elliptio dilatata — Watters et al. (2009)

Unio arctior Lea, 1838
Lea, 1836. Synopsis Fam. Naiades: 39. [nomen nudum]
Lea, 1838. Trans. Amer. Phil. Soc. 6 [O. 2]: 10, pl. 4, fig. 10.
Type(s): HOLOTYPE USNM_86103, Ohio R., Cincinnati, Ohio.

Unio (sec. Elliptio) gibbosus — Simpson (1900), Simpson (1914)
Unio (s.s.) gibbosus — Call (1900)
Unio arctior — de Gregorio (1914)
Elliptio dilatata — Utterback (1915), Oesch (1984), Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)
Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)

Unio stonensis Lea, 1840
Lea, 1840. Proc. Amer. Phil. Soc. 1: 286.
Lea, 1842. Trans. Amer. Phil. Soc. 8 [O. 3]: 195 [33], pl. 8, fig. 5.
Type(s): HOLOTYPE USNM_84969, Stone R., Tenn.

Unio (sec. Elliptio) stonensis — Simpson (1900), Simpson (1914)
Unio (s.s.) gibbosus — Call (1900)
— de Gregorio (1914)
Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)
Elliptio dilatata — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio gibbosus var. armathwaitensis B.H. Wright, 1898
B.H. Wright, 1898. Nautilus 11(11): 123.
Type(s): LECTOTYPE USNM_150523, Armathwaite, Fentress Co., Tenn.

Unio (sec. Elliptio) gibbosus var. armathwaitensis — Simpson (1900), Simpson (1914)
Elliptio (Eurynaia [sic]) dilatatus-armathwaitensis — Frierson (1927)
Elliptio (Eurynia) nasutus armathwaitensis — Haas (1969)
Elliptio dilatata — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio (sec. Elliptio) gibbosus var. delicatus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 704.
Simpson, 1914. Descr. Cat. Naiades: 600.
Type(s): LECTOTYPE USNM_128797, St. Francis R., Greenway, Clay Co., Arkansas.

Unio (sec. Elliptio) gibbosus var. delicatus — Simpson (1900), Simpson (1914)
Elliptio dilatata delicata — Utterback (1915)
Elliptio (Eurynaia [sic]) dilatatus-delicatus — Frierson (1927)
Elliptio dilatatus delicatus — F.C. Baker (1928)
Elliptio (Eurynia) nasutus delicatus — Haas (1969)
Elliptio dilatata — R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio propeverutus de Gregorio, 1914
de Gregorio, 1914. Il Nat. Siciliano 2: 38, pl. 3, figs. 1a-d.

Unio propeverutus — de Gregorio (1914)
Elliptio dilatata — Williams et al. (2008), Watters et al. (2009)

Elliptio dilatata var. sterkii Grier, 1918
Grier, 1918. Nautilus 32(1): 9.
Type(s): HOLOTYPE (ORIG. DESIG.) CM_61.4628, Presque Isle Bay, Erie, Erie County, Pennsylvania.

— Frierson (1927)
Elliptio dilatatus sterkii — F.C. Baker (1928)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)
Elliptio (s.s.) dilatata — Burch (1975)
Elliptio dilatata — R.I. Johnson (1980), Strayer & Jirka (1997), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio arctatus Ferussac, 1835
‘Conrad’ Ferussac, 1835. Mag. Zool. 5: 29.

Unio (sec. Elliptio) gibbosus — Simpson (1900), Simpson (1914)
Elliptio (Eurynaia [sic]) dilatatus — Frierson (1927)
Elliptio (Eurynia) nasutus nasutus — Haas (1969)

Unio torulosus Ferussac, 1835
‘Rafinesque’ Ferussac, 1835. Mag. Zool. 5: 28.

Unio (sec. Elliptio) gibbosus — Simpson (1900), Simpson (1914)

Unio bicolar Lea, 1852
‘Rafinesque’ Lea, 1852. Synopsis Fam. Naiades: 57.

Elliptio dilatata var. subgibbosa Utterback, 1915
‘Lea’ Utterback, 1915. Amer. Midl. Nat. 4(5): 202-203, pl. 21, figs. 68a-d.

Elliptio dilatata — Parmalee & Bogan (1998), Watters et al. (2009)

Unio arctiro Howells et al., 1996
‘Lea’ Howells et al., 1996. Freshw. Mussels Tex.: 51.