species Eurynia dilatata (Rafinesque, 1820): synonymy

Unio nasuta Lamarck, 1819

(homonym of Unio nasutus Say, 1817)
Lamarck, 1819. Hist. Natur. Anim. sans Vert. 6: 75, sp. 22.
SYNTYPE MNHN_MPL_0022, rapporte Lac Erie.

Unio (sec. Elliptio) gibbosus — Simpson (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus — 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)

Unio (Eurynia) dilatata Rafinesque, 1820

(renamed Obliquaria violacea Rafinesque, 1831)
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.
LECTOTYPE ANSP_20248, Kentucky River.

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)
Eurynaia [sic] dilatata — Morrison (1966)
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), Campbell & Lydeard (2026), Barraza et al. (2026)
Elliptio (Eurynia) dilatata — Campbell & Lydeard (2012), Burlakova et al. (2012), Perkins et al. (2017)
Eurynia (Elliptio) dilatata — Porto-Hannes et al. (2021)

Obliquaria (Ellipsaria) atroviolacea Rafinesque, 1820

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

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.

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

Obliquaria (Ellipsaria) sinuata Rafinesque, 1820

(renamed Unio cultratus Rafinesque, 1831)
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 321 [also as ‘Unio sinuata’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 63.
LECTOTYPE ANSP_20252, Kentucky River.

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

Unio mucronatus Barnes, 1823

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

Unio (sec. Elliptio) gibbosus — Simpson (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus — 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)

Unio gibbosus Barnes, 1823

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

Unio (sec. Elliptio) gibbosus — Simpson (1900)
Unio (s.s.) gibbosus — Call (1900)
Unio gibbosus — Ortmann (1909), Ortmann (1909), Ortmann (1909), Ortmann (1910), Ortmann (1911)
Elliptio gibbosus — Ortmann (1911), Ortmann (1912)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus — Simpson (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)

Obliquaria bicolor 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)

Obliquaria violacea Rafinesque, 1831

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

Bariosta fulvus Rafinesque, 1831

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

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

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

Bariosta fulvus var. rufa Rafinesque, 1831

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

Unio cultratus Rafinesque, 1831

(new name for Obliquaria (Ellipsaria) sinuata Rafinesque, 1820)
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 ‘Rafinesque’ of Authors

(reference to Unio (Eurynia) dilatata Rafinesque, 1820)
‘Rafinesque’ of Authors.
Say, 1834. Amer. Conch. 1(6): sp. 9 [synonymy].
Conrad, 1836. Monogr. Fam. Unionidae 1(5): 42, pl. 21.

Unio (sec. Elliptio) gibbosus — Simpson (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus — 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.
HOLOTYPE USNM_86103, Ohio R., Cincinnati, Ohio.

Unio (sec. Elliptio) gibbosus — Simpson (1900)
Unio (s.s.) gibbosus — Call (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus — Simpson (1914)
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.
HOLOTYPE USNM_84969, Stone R., Tenn.

Unio (sec. Elliptio) stonensis — Simpson (1900)
Unio (s.s.) gibbosus — Call (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) stonensis — 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)

Unio gibbosus var. armathwaitensis B.H. Wright, 1898

(intro'd as intra-sp. of Unio gibbosus Barnes, 1823)
B.H. Wright, 1898. Nautilus 11(11): 123.
LECTOTYPE USNM_150523 (by R.I. Johnson, 1967: 5), Armathwaite, Fentress Co., Tenn.

Unio (sec. Elliptio) gibbosus var. armathwaitensis — Simpson (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus var. armathwaitensis — 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

(homonym of Unio delicatus Lea, 1863; intro'd as intra-sp. of Unio gibbosus Barnes, 1823)
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 704.
Simpson, 1914. Descr. Cat. Naiades: 600.
LECTOTYPE USNM_128797, St. Francis R., Greenway, Clay Co., Arkansas.

Unio (sec. Elliptio) gibbosus var. delicatus — Simpson (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus var. delicatus — 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

(intro'd as intra-sp. of Unio (Eurynia) dilatata Rafinesque, 1820)
Grier, 1918. Nautilus 32(1): 9.
HOLOTYPE (ORIG. DESIG.) CM_61.4628, Presque Isle Bay, Erie, Erie County, Pennsylvania.

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)

Eurynia dilatate Barraza et al., 2026

(error for Unio (Eurynia) dilatata Rafinesque, 1820)
‘Rafinesque’ Barraza et al., 2026. Check List 22(4): Table 1.

Unio arctatus Ferussac, 1835

(misidentified reference to Unio arctatus Conrad, 1834)
‘Conrad’ Ferussac, 1835. Mag. Zool. 5(59-60): 29.

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

Unio torulosus Ferussac, 1835

(misidentified reference to Amblema torulosa Rafinesque, 1820)
‘Rafinesque’ Ferussac, 1835. Mag. Zool. 5(59-60): 28.

Unio (sec. Elliptio) gibbosus — Simpson (1900)
Unio (sec. Elliptio) (Group of U. gibbosus) gibbosus — Simpson (1914)

Unio bicolar Lea, 1852

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

Elliptio dilatata var. subgibbosa Utterback, 1915

(misidentified reference to Unio subgibbosus Lea, 1857)
‘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

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