Unio nasuta Lamarck, 1819
Lamarck, 1819. Hist. Natur. Anim. sans Vert. 6: 75, sp. 22.
(homonym of Unio nasutus Say, 1817)
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.
(renamed Unio cultratus Rafinesque, 1831)
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.
(renamed Obliquaria violacea Rafinesque, 1831)
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)
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.
(intro'd as intra-sp. of Bariosta fulvus Rafinesque, 1831)

Bariosta fulvus var. rufa Rafinesque, 1831
Rafinesque, 1831. Continuation: 3.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 74.
(intro'd as intra-sp. of Bariosta fulvus Rafinesque, 1831)

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.
(new name for Unio (Eurynia) dilatata Rafinesque, 1820)

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.
(new name for Obliquaria (Ellipsaria) sinuata Rafinesque, 1820)

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.
(reference to Unio (Eurynia) dilatata Rafinesque, 1820)

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.
(intro'd as intra-sp. of Unio gibbosus Barnes, 1823)
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.
(intro'd as intra-sp. of Unio gibbosus Barnes, 1823; homonym of Unio delicatus Lea, 1863)
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.
(intro'd as intra-sp. of Unio (Eurynia) dilatata Rafinesque, 1820)
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.
(misidentified reference to Unio arctatus Conrad, 1834)

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.
(misidentified reference to Amblema torulosa Rafinesque, 1820)

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

Unio bicolar Lea, 1852
‘Rafinesque’ Lea, 1852. Synopsis Fam. Naiades: 57.
(error for Obliquaria bicolor Rafinesque, 1831)

Elliptio dilatata var. subgibbosa Utterback, 1915
‘Lea’ Utterback, 1915. Amer. Midl. Nat. 4(5): 202-203, pl. 21, figs. 68a-d.
(misidentified reference to Unio subgibbosus Lea, 1857)

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

Unio arctiro Howells et al., 1996
‘Lea’ Howells et al., 1996. Freshw. Mussels Tex.: 51.
(error for Unio arctior Lea, 1838)