Unio productus Conrad, 1836
Conrad, 1836, Monogr. Fam. Unionidae 1(3): 31, pl. 14, fig. 1.
Conrad, 1853, Proc. Acad. Nat. Sci. 6: 255.
Type(s): HOLOTYPE ANSP_41397, [no locality available - North America].

Unio productus — Conrad (1836), Hanley (1843), Küster (1853), Adams & Adams (1857), B.H. Wright (1888), Ortmann (1910)
Margarita (Unio) productus — Lea (1836), Lea (1838)
Eurynia producta — Agassiz (1852)
Margaron (Unio) productus — Lea (1852), Lea (1870)
Unio (Eurinea) productus — Conrad (1853)
Unio (sec. Elliptio) productus — Simpson (1900), Simpson (1914)
Elliptio productus — Ortmann (1911), Ortmann (1912), Ortmann & Walker (1922)
Elliptio (s.s.) productus — Frierson (1927), Haas (1969)
Elliptio (s.s.) lanceolata — R.I. Johnson (1970), Burch (1975)
Elliptio producta — Davis (1984), Turgeon et al. (1988), Williams et al. (1993), Turgeon et al. (1998), ..., Graf & Cummings (2021), FMCS (2021), Bieler (2021), Hopper et al. (2023)

Unio nasutidus Lea, 1863
Lea, 1863, Proc. Acad. Nat. Sci. 15: 192.

Unio nasutidus — Lea (1863)
Unio (sec. Elliptio) nasutulus — Simpson (1900), Simpson (1914)
Elliptio (s.s.) lanceolata — R.I. Johnson (1970), Burch (1975)
Elliptio nasutilus — Bogan (2002), Inoue et al. (2018)
Elliptio producta — Bieler (2021)

Unio nasutulus Lea, 1866
Lea, 1866, Jour. Acad. Nat. Sci. 6 [O. 11]: 12 [16], pl. 3, fig. 9.
(error for Unio nasutidus Lea, 1863)
Type(s): HOLOTYPE USNM_86027, Livingston Cr., Brunswick Co., N.C.

Unio nasutulus — Lea (1866), B.H. Wright (1888)
Margaron (Unio) nasutulus — Lea (1870)
Unio (sec. Elliptio) nasutulus — Simpson (1900), Simpson (1914)
Elliptio (s.s.) productus — Frierson (1927), Haas (1969)
Elliptio (s.s.) lanceolata — R.I. Johnson (1970), Burch (1975)
Elliptio nasutilus — Perkins et al. (2017)
Elliptio producta — Bieler (2021)

Unio nasutus Conrad, 1838
‘Say’ Conrad, 1838, Monogr. Fam. Unionidae 2(11): 38, pl. 18, fig. 1 [upper]. [in part]
Conrad, 1838, Monogr. Fam. Unionidae 2(11): back cover correginda [as ‘U. fisherianus Lea’].
(misidentified reference to Unio nasutus Say, 1817)

Unio nasutus — Conrad (1838), De Kay (1843), Küster (1861)
Unio fisherianus — Conrad (1853)
Unio (sec. Elliptio) fisherianus — Simpson (1900), Simpson (1914)
Elliptio (s.s.) productus — Frierson (1927), Haas (1969)

Unio barrotti Küster, 1861
‘Lea’ Küster, 1861, Conchyl. Cab. 9(2): 189, pl. 59, fig. 6.

Unio barrotti — Küster (1861)
Unio (sec. Elliptio) productus — Simpson (1900), Simpson (1914)
Elliptio (s.s.) productus — Frierson (1927), Haas (1969)

Unio nasutilus Simpson, 1900
‘Lea’ of Authors.
Simpson, 1900, Proc. U.S. Nat. Mus. 22: 735.
Simpson, 1914, Descr. Cat. Naiades: 691.
R.I. Johnson, 1970, Bull. MCZ 140(6): 334.
Burch, 1975, Freshw. Unio. North Amer.: 167.
Bogan, 2002, Workbook Key Freshw. Biv. NC: Table 5.
Perkins et al., 2017, Conserv. Genet. 18: 752.
Inoue et al., 2018, Invert. Syst. 32: Table S2.
(error for Unio nasutidus Lea, 1863)

Unio nasutilus — Simpson (1900)
Elliptio producta — Bieler (2021)

Unio nasululus Simpson, 1914
Simpson, 1914, Descr. Cat. Naiades: 691.
(error for Unio nasutulus Lea, 1866)

Unio nasululus — Simpson (1914)
Elliptio producta — Bieler (2021)

Taxonomic History (since 1900)

Unio (sec. Elliptio) productus — Simpson (1900), Simpson (1914)
Unio (sec. Elliptio) fisherianus — Simpson (1900), Simpson (1914)
Unio (sec. Elliptio) nasutulus — Simpson (1900), Simpson (1914)
Unio nasutilus — Simpson (1900)
Unio productus — Ortmann (1910)
Elliptio productus — Ortmann (1911), Ortmann (1912), Ortmann & Walker (1922)
Unio nasululus — Simpson (1914)
Elliptio (s.s.) productus — Frierson (1927), Haas (1969)
Elliptio (s.s.) lanceolata — R.I. Johnson (1970), Burch (1975)
Elliptio producta — Davis (1984), Turgeon et al. (1988), Williams et al. (1993), Turgeon et al. (1998), ..., Graf & Cummings (2021), FMCS (2021), Bieler (2021), Hopper et al. (2023)
Elliptio nasutilus — Bogan (2002), Perkins et al. (2017), Inoue et al. (2018)