Obliquaria (Quadrula) quadrula Rafinesque, 1820
Rafinesque, 1820, Ann. Gén. Sci. Phys. 5 (13): 307 [also as ‘Unio quadrula’].
Rafinesque, 1864, [in] Binney & Tryon, reprint: 51.
Type(s): NEOTYPE ANSP_20224, Salt River.

Obliquaria (Quadrula) quadrula — Rafinesque (1820)
Unio quadrulus — Ferussac (1835), Conrad (1840), Küster (1861)
Unio (Theliderma) quadrulus — Conrad (1853)
Unio quadratus — Reeve (1864)
Unio (sec. Quadrula) quadrulus — Paetel (1890)
Quadrula quadrula — Utterback (1915), Vanatta (1915), Ortmann & Walker (1922), Ortmann (1924), ..., Wu et al. (2024), Dai et al. (2024), Dai et al. (2024), Wu et al. (2024)
Quadrula (s.s.) quadrula — Frierson (1927), F.C. Baker (1928), Haas (1969)
Quadrula (s.s.) gigantea — Haas (1930)
Quadrula (s.s.) quadrula quadrula — Haas (1969)
Obliquaria quadrula — Burch (1975)
Quadrula quedrula — Contreras-Arquieta (2000)
Quadrula quadrula quadrula — ITIS (2012)
Q. quadrula — Sheng et al. (2014)

Unio apiculatus Say, 1829
Say, 1829, New Harm. Dissem. 2(20): 309, sp. 8.
Say, 1834, Amer. Conch. 6: pl. 52.
Say, 1858, [in] Binney, Compl. Writings T. Say: 131, 207, 225.

Unio apiculatus — Say (1829), Ferussac (1835), Conrad (1837), Hanley (1843), Reeve (1864), B.H. Wright (1888), Singley (1893)
Margarita (Unio) apiculatus — Lea (1836), Lea (1838)
Margaron (Unio) apiculatus — Lea (1852), Lea (1870)
Unio (Theliderma) apiculatus — Conrad (1853)
Unio (Quadrula) apiculatus — Adams & Adams (1857)
Unio (sec. Quadrula) apiculatus — Paetel (1890)
Quadrula (sec. Theliderma) apiculata — Simpson (1900), Simpson (1914)
Quadrula apiculata — Ortmann (1910), R.I. Johnson (1980), Davis & Fuller (1981), Turgeon et al. (1988), ..., Pfeiffer et al. (2019), Pfeiffer et al. (2019), Inoue et al. (2020), Hauck et al. (2023)
Quadrula (s.s.) quadrula-apiculata — Frierson (1927)
Quadrula (s.s.) quadrula apiculata — Haas (1969)
Quadrula quadrula — Burch (1975), Lopes-Lima et al. (2019), Graf & Cummings (2021), FMCS (2021)

Unio rumphianus Lea, 1852
Lea, 1852, Trans. Amer. Phil. Soc. 10 [O. 5]: 276 [32], pl. 22, fig. 34.
Lea, 1852, Proc. Amer. Phil. Soc. 5: 252. [nomen nudum]
Type(s): HOLOTYPE USNM_84189, West Georgia.

Unio rumphianus — Lea (1852), Conrad (1853), B.H. Wright (1888)
Margaron (Unio) rumphianus — Lea (1852), Lea (1870)
Unio (Quadrula) rumphianus — Adams & Adams (1857)
Quadrula (sec. Theliderma) rumphiana — Simpson (1900), Simpson (1914)
Quadrula (s.s.) quadrula-rumphiana — Frierson (1927)
Quadrula (s.s.) quadrula rumphiana — Haas (1969)
Quadrula quadrula — Burch (1975), Lopes-Lima et al. (2019), Graf & Cummings (2021), FMCS (2021)
Quadrula rumphiana — Turgeon et al. (1988), Williams et al. (1993), Turgeon et al. (1998), Lydeard et al. (1999), ..., Williams et al. (2017), Inoue et al. (2018), Burlakova et al. (2019), Hauck et al. (2023)

Unio asper Lea, 1831
Lea, 1831, Trans. Amer. Phil. Soc. 4 [O. 1]: 85 [95], pl. 9, fig. 15.
Type(s): UNKNOWN USNM_84212, Claiborne, Ala. R., Alabama.

Unio asper — Lea (1831), Jay (1835), Hanley (1843), Conrad (1853), Reeve (1864), B.H. Wright (1888), Singley (1893)
Unio apiculatus — Ferussac (1835), Conrad (1837)
Margarita (Unio) asper — Lea (1836), Lea (1838)
Margaron (Unio) asper — Lea (1852), Lea (1870)
Unio (Quadrula) asper — Mörch (1853), Adams & Adams (1857)
Unio (sec. Quadrula) apiculatus vr. asper — Paetel (1890)
Quadrula (sec. Theliderma) asper — Simpson (1900)
Quadrula aspera — Ortmann (1912), Utterback (1915)
Quadrula (sec. Theliderma) aspera — Simpson (1914)
Quadrula (s.s.) quadrula-aspera — Frierson (1927)
Quadrula (s.s.) quadrula aspera — Haas (1969)
Quadrula quadrula — Burch (1975), R.I. Johnson (1980), Vidrine (1993), Lopes-Lima et al. (2019)
Quadrula apiculata — Williams et al. (2008)

Unio forsheyi Lea, 1859
Lea, 1859, Proc. Acad. Nat. Sci. 11: 155.
Lea, 1860, Jour. Acad. Nat. Sci. 4 [O. 8]: 357 [39], pl. 60, fig. 182.
Type(s): HOLOTYPE USNM_84169, Texas.

Unio forsheyi — Lea (1859), Reeve (1864), B.H. Wright (1888), Singley (1893)
Margaron (Unio) forsheyi — Lea (1870)
Quadrula (sec. Theliderma) forsheyi — Simpson (1900), Simpson (1914)
Quadrula forsheyi — Ortmann (1910)
Quadrula (s.s.) quadrula-forsheyi — Frierson (1927)
Quadrula (s.s.) quadrula forsheyi — Haas (1969)
Quadrula quadrula — Burch (1975), Howells et al. (1996), Lopes-Lima et al. (2019)
Quadrula apiculata — Williams et al. (2008)

Unio speciosus Lea, 1862
Lea, 1862, Proc. Acad. Nat. Sci. 14: 168.
Lea, 1862, Jour. Acad. Nat. Sci. 5 [O. 9]: 207 [29], pl. 31, fig. 276.
Type(s): HOLOTYPE USNM_84172, Leon Co., Texas.

Unio speciosus — Lea (1862), Sowerby (1868), B.H. Wright (1888), Singley (1893), Call (1895)
Margaron (Unio) speciosus — Lea (1870)
Quadrula (sec. Theliderma) speciosa — Simpson (1900), Simpson (1914)
Quadrula speciosa — Ortmann (1910)
Quadrula (s.s.) quadrula-speciosa — Frierson (1927)
Quadrula (s.s.) quadrula speciosa — Haas (1969)
Quadrula quadrula — Burch (1975)
Quadrula apiculata — R.I. Johnson (1999)

Unio rugosus Barnes, 1823
Barnes, 1823, Amer. J. Sci. 6 (1-2): 126, pl. 8, fig. 9a-b.
(homonym of Unio rugosa Poiret, 1801)

Unio rugosus — Barnes (1823), Hildreth (1828)
Unio quadrulus — Ferussac (1835), Conrad (1840)
Margarita (Unio) metanever — Lea (1836), Lea (1838)
Unio (Theliderma) rugosus — Swainson (1840)
Quadrula rugosus — Agassiz (1852)
Margaron (Unio) metanevrus — Lea (1852), Lea (1870)
Unio metaneurus — Conrad (1853)
Unio metanever — Reeve (1864)
Unio metanevrus — Call (1895)
Quadrula quadrula — Ortmann & Walker (1922), Burch (1975), R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Lopes-Lima et al. (2019)
Quadrula (s.s.) quadrula — Frierson (1927), F.C. Baker (1928)
Quadrula (s.s.) gigantea — Haas (1930)
Quadrula (s.s.) quadrula quadrula — Haas (1969)
Quadrula fragosa — Watters et al. (2009)

Unio dombeyanus Barnes, 1828
Barnes, 1828, Amer. J. Sci. 13(2): 360.
(misidentified reference to Unio dombeyana Humboldt & Bonpland, 1827)

Unio dombeyanus — Barnes (1828)
Quadrula (s.s.) quadrula — Frierson (1927)

Unio lacrymosus Lea, 1828
Lea, 1828, Trans. Amer. Phil. Soc. 3 [O. 1]: 272 [14], pl. 6, fig. 8.
Type(s): HOLOTYPE USNM_84165, Cincinnati, Ohio.

Unio lacrymosus — Lea (1828), Lea (1829), Ravenel (1834), Ferussac (1835), Küster (1853), B.H. Wright (1888)
Margarita (Unio) lacrymosus — Lea (1836), Lea (1838)
Unio quadrulus — Conrad (1840), Conrad (1853)
Unio (Theliderma) lachrymosa — Swainson (1840)
Unio lachrymosus — Hanley (1843), Reeve (1864), Call (1895)
Margaron (Unio) lacrymosus — Lea (1852), Lea (1870)
Unio (Quadrula) lachrymosus — Adams & Adams (1857)
Quadrula (sec. Theliderma) lachrymosa — Simpson (1900), Simpson (1914)
Unio (s.s.) lachrymosus — Call (1900)
Quadrula lachrymosus — Ortmann (1909)
Quadrula lachrymosa — Ortmann (1909), Ortmann (1910), Ortmann (1910), Ortmann (1912)
Quadrula quadrula — Utterback (1915), Vanatta (1915), Ortmann & Walker (1922), Burch (1975), ..., Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), Lopes-Lima et al. (2019)
Quadrula (s.s.) quadrula — Frierson (1927), F.C. Baker (1928)
Quadrula (s.s.) quadrula quadrula — Haas (1969)

Unio asperrimus Lea, 1831
Lea, 1831, Trans. Amer. Phil. Soc. 4 [O. 1]: 71 [81], pl. 5, fig. 3.
Type(s): HOLOTYPE USNM_84174, Cincinnati, Ohio.

Unio asperrimus — Lea (1831), Jay (1835), Hanley (1843), B.H. Wright (1888), Singley (1893), Pilsbry & Rhoads (1896), de Gregorio (1914)
Unio asperimus — Ravenel (1834)
Unio quadrulus — Ferussac (1835), Conrad (1840), Conrad (1853), Küster (1861)
Margarita (Unio) asperrimus — Lea (1836), Lea (1838)
Margaron (Unio) asperrimus — Lea (1852), Lea (1870)
Unio (Quadrula) asperrimus — Adams & Adams (1857)
Unio quadratus — Reeve (1864)
Unio (sec. Quadrula) quadrulus — Paetel (1890)
Unio lachrymosus — Call (1895)
Quadrula (sec. Theliderma) lachrymosa — Simpson (1900), Simpson (1914)
Unio (s.s.) lachrymosus — Call (1900)
Quadrula quadrula — Utterback (1915), Ortmann & Walker (1922), Burch (1975), R.I. Johnson (1980), ..., Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), Lopes-Lima et al. (2019)
Quadrula (s.s.) quadrula — Frierson (1927), F.C. Baker (1928)
Quadrula (s.s.) quadrula quadrula — Haas (1969)

Unio asperimus Ravenel, 1834
‘Lea’ Ravenel, 1834, Cat. Rec. Shells: 5.
(error for Unio asperrimus Lea, 1831)

Unio asperimus — Ravenel (1834)

Unio quadrulus Say, 1834
‘Rafinesque’ of Authors.
Say, 1834, Amer. Conch. 6: pl. 53.
Conrad, 1840, Monogr. Fam. Unionidae 2(13): 112, pl. 62.
(reference to Obliquaria (Quadrula) quadrula Rafinesque, 1820)

Unio quadrulus — Say (1834), Conrad (1840), Conrad (1853), Küster (1861)
Unio lacrymosus — Ravenel (1834), Ferussac (1835)
Margarita (Unio) asperrimus — Lea (1838)
Margaron (Unio) asperrimus — Lea (1852), Lea (1870)
Unio quadratus — Reeve (1864)
Unio lachrymosus — Call (1895)
Quadrula (sec. Theliderma) lachrymosa — Simpson (1900), Simpson (1914)
Quadrula quadrula — Utterback (1915), Watters et al. (2009)

Unio asper Jay, 1839
‘Lea’ Jay, 1839, Cat. Rec. Shells: 55.
(reference to Unio asper Lea, 1831)

Unio asper — Jay (1839)
Unio apiculatus — Conrad (1853)

Quadrula lachrymosa Swainson, 1840
‘Lea’ of Authors.
Swainson, 1840, Treat. Malacol.: 378.
Hanley, 1843, Illustr. Descr. Cat. Rec. Bivalve Shells: 177.
Conrad, 1853, Proc. Acad. Nat. Sci. 6: 256.
Adams & Adams, 1857, Gen. Rec. Moll. 2(31-32): 497.
Reeve, 1864, Conch. Icon. 16: pl. 9, sp. 33.
Call, 1895, Trans. Acad. Sci. St. Louis 7: 21.
F.C. Baker, 1898, Bull. Chicago Acad. Sci. 3(1): 83, pl. 25, fig. 1; pl. 12, fig. 2.
Simpson, 1900, Proc. U.S. Nat. Mus. 22: 776.
Call, 1900, Ind. Dept. Geol. Nat. Res. (1899): 489.
Ortmann, 1909, Nautilus 22(10): 100.
Ortmann, 1909, Ann. Carnegie Mus. 5: 199.
Ortmann, 1910, Nautilus 23(11): 140.
Ortmann, 1910, Nautilus 23: 116.
Ortmann, 1912, Ann. Carnegie Mus. 8: 253.
Simpson, 1914, Descr. Cat. Naiades: 839, 841.
Vanatta, 1915, Proc. Acad. Nat. Sci. 67: 556.
Ortmann & Walker, 1922, Occ. Pap. Mus. Zool. Univ. Mich. (112): 14, 16.
Frierson, 1927, Check List N. Amer. Naiades: 47.
F.C. Baker, 1928, Bull. Wisconsin Geol. Nat. Hist. Survey 70(2): 84.
R.I. Johnson, 1980, Bull. MCZ 149(2): 90.
Vidrine, 1993, Histr. Distr. Freshw. Mussels LA: 53.
Strayer & Jirka, 1997, Pearly Mussels NY (26): 98.
(error for Unio lacrymosus Lea, 1828)

Quadrula lachrymosa — Swainson (1840)
Quadrula quadrula — Utterback (1915), Murray & Leonard (1962), Oesch (1984), Vidrine (1993), Parmalee & Bogan (1998), Watters et al. (2009)

Unio nobilis Conrad, 1854
Conrad, 1854, Jour. Acad. Nat. Sci. 2(4): 297, pl. 27, figs. 2. [in part]
(misidentified reference to Unio nobilis Conrad, 1854)

Unio nobilis — Conrad (1854)
Unio (Theliderma) nobilis — Conrad (1853)
Margaron (Unio) asperrimus — Lea (1870)
Quadrula (sec. Theliderma) apiculata — Simpson (1900), Simpson (1914)
Quadrula nobilis — Utterback (1915)
Quadrula quadrula — Burch (1975), R.I. Johnson (1980), Howells et al. (1996)
Quadrula apiculata — Vidrine (1993), Parmalee & Bogan (1998)

Unio blandianus Lea, 1856
Lea, 1856, Proc. Acad. Nat. Sci. 8: 263.
Lea, 1857, Proc. Acad. Nat. Sci. 9: 31.
Lea, 1858, Jour. Acad. Nat. Sci. 4 [O. 6]: 65, pl. 11, fig. 47.
Type(s): HOLOTYPE USNM_84190, Othcaloosa Cr., Ga.

Unio blandianus — Lea (1856), Sowerby (1868), B.H. Wright (1888)
Margaron (Unio) blandianus — Lea (1870)
Unio (sec. Rotundaria) blandianus — Paetel (1890)
Quadrula (sec. Theliderma) rumphiana — Simpson (1900), Simpson (1914)
Quadrula (s.s.) quadrula-rumphiana — Frierson (1927)
Quadrula (s.s.) quadrula rumphiana — Haas (1969)
Quadrula quadrula — Burch (1975), Lopes-Lima et al. (2019)
Quadrula rumphiana — Williams et al. (2008)

Unio quadratus Reeve, 1864
‘Rafinesque’ Reeve, 1864, Conch. Icon. 16: pl. 6, sp. 24.
(error for Obliquaria (Quadrula) quadrula Rafinesque, 1820)

Unio quadratus — Reeve (1864)
Margaron (Unio) lacrymosus — Lea (1870)
Quadrula (sec. Theliderma) lachrymosa — Simpson (1900), Simpson (1914)
Quadrula (s.s.) quadrula — Frierson (1927)
Quadrula (s.s.) quadrula quadrula — Haas (1969)
Quadrula quadrula — Parmalee & Bogan (1998), Watters et al. (2009)

Unio turgidus Reeve, 1864
‘Lea’ Reeve, 1864, Conch. Icon. 16: pl. 3, sp. 10.
(misidentified reference to Unio turgidus Lea, 1838)

Unio turgidus — Reeve (1864)
Quadrula (sec. Theliderma) asper — Simpson (1900)
Quadrula (sec. Theliderma) aspera — Simpson (1914)

Unio lunulatus Pratt, 1876
Pratt, 1876, Proc. Davenport Acad. Nat. Sci. 1: 168, pl. 31, fig. 1a-b [as ‘unul atus’; corrected in Errata].
(correct name for Unio unul atus Pratt, 1876)

Unio lunulatus — Pratt (1876)
Unio lachrymosus — Call (1895)
Quadrula (sec. Theliderma) lachrymosa var. lunulata — Simpson (1900)
Tritogonia nobilis — Simpson (1914)
Quadrula (s.s.) quadrula — Frierson (1927)
Quadrula (s.s.) quadrula quadrula — Haas (1969)
Quadrula quadrula — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), Lopes-Lima et al. (2019)

Unio unul atus Pratt, 1876
Pratt, 1876, Proc. Davenport Acad. Nat. Sci. 1: 168.
(incorrect original spelling of Unio lunulatus Pratt, 1876)

Unio unul atus — Pratt (1876)
Quadrula quadrula — Lopes-Lima et al. (2019)

Quadrula quadrula contraryensis Utterback, 1915
Utterback, 1915, Amer. Midl. Nat. 4(4): 138, pl. 18, figs. 47a-b.
(intro'd as intra-sp. of Obliquaria (Quadrula) quadrula Rafinesque, 1820)
Type(s): NEOTYPE CM_61.6892, Lake Contrary, St. Joseph, Buchanan Co., Missouri.

Quadrula quadrula contraryensis — Utterback (1915)
Quadrula quadrula — Burch (1975), R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), Lopes-Lima et al. (2019)

Quadrula (Quadrula) quadrula bullocki F.C. Baker, 1928
F.C. Baker, 1928, Bull. Wisconsin Geol. Nat. Hist. Survey 70(2): 87, pl. 46, figs. 1-3.
(intro'd as intra-sp. of Obliquaria (Quadrula) quadrula Rafinesque, 1820)
Type(s): HOLOTYPE (ORIG. DESIG.) UMMZ_209203, Fox River, nr. De Pere, Wisc.

Quadrula (Quadrula) quadrula bullocki — F.C. Baker (1928)
Quadrula (s.s.) quadrula bullocki — F.C. Baker (1928)
Quadrula quadrula — Clarke (1973), Burch (1975), R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), Lopes-Lima et al. (2019)

Quadrula (s.s.) gigantea Haas, 1930
‘Raf.’ Haas, 1930, Senckenbergiana 12(6): 327.
(error for Obliquaria (Quadrula) quadrula Rafinesque, 1820)

Quadrula (s.s.) gigantea — Haas (1930)

Quadrula contrayensis R.I. Johnson, 1969
‘Utterback’ R.I. Johnson, 1969, Nautilus 82(4): 132.
(error for Quadrula quadrula contraryensis Utterback, 1915)

Quadrula contrayensis — R.I. Johnson (1969)
Quadrula quadrula — Parmalee & Bogan (1998)

Quadrula quedrula Contreras-Arquieta, 2000
‘Rafinesque’ Contreras-Arquieta, 2000, Mexicoa 2(1): 44.
(error for Obliquaria (Quadrula) quadrula Rafinesque, 1820)

Quadrula quedrula — Contreras-Arquieta (2000)

Taxonomic History (since 1900)

Quadrula (sec. Theliderma) lachrymosa — Simpson (1900), Simpson (1914)
Unio (s.s.) lachrymosus — Call (1900)
Quadrula (sec. Theliderma) apiculata — Simpson (1900), Simpson (1914)
Quadrula (sec. Theliderma) asper — Simpson (1900)
Quadrula (sec. Theliderma) rumphiana — Simpson (1900), Simpson (1914)
Quadrula (sec. Theliderma) forsheyi — Simpson (1900), Simpson (1914)
Quadrula (sec. Theliderma) speciosa — Simpson (1900), Simpson (1914)
Quadrula (sec. Theliderma) lachrymosa var. lunulata — Simpson (1900)
Quadrula lachrymosus — Ortmann (1909)
Quadrula lachrymosa — Ortmann (1909), Ortmann (1910), Ortmann (1910), Ortmann (1912)
Quadrula apiculata — Ortmann (1910), R.I. Johnson (1980), Davis & Fuller (1981), Turgeon et al. (1988), ..., Pfeiffer et al. (2019), Pfeiffer et al. (2019), Inoue et al. (2020), Hauck et al. (2023)
Quadrula forsheyi — Ortmann (1910)
Quadrula speciosa — Ortmann (1910)
Quadrula aspera — Ortmann (1912), Utterback (1915)
Quadrula (sec. Theliderma) aspera — Simpson (1914)
Unio asperrimus — de Gregorio (1914)
Tritogonia nobilis — Simpson (1914)
Quadrula quadrula — Utterback (1915), Vanatta (1915), Ortmann & Walker (1922), Ortmann (1924), ..., Wu et al. (2024), Dai et al. (2024), Dai et al. (2024), Wu et al. (2024)
Quadrula nobilis — Utterback (1915)
Quadrula quadrula contraryensis — Utterback (1915)
Quadrula (s.s.) quadrula — Frierson (1927), F.C. Baker (1928), Haas (1969)
Quadrula (s.s.) quadrula-apiculata — Frierson (1927)
Quadrula (s.s.) quadrula-aspera — Frierson (1927)
Quadrula (s.s.) quadrula-rumphiana — Frierson (1927)
Quadrula (s.s.) quadrula-forsheyi — Frierson (1927)
Quadrula (s.s.) quadrula-speciosa — Frierson (1927)
Quadrula (Quadrula) quadrula bullocki — F.C. Baker (1928)
Quadrula (s.s.) quadrula bullocki — F.C. Baker (1928)
Quadrula (s.s.) gigantea — Haas (1930)
Quadrula (s.s.) quadrula quadrula — Haas (1969)
Quadrula (s.s.) quadrula apiculata — Haas (1969)
Quadrula (s.s.) quadrula aspera — Haas (1969)
Quadrula (s.s.) quadrula rumphiana — Haas (1969)
Quadrula (s.s.) quadrula forsheyi — Haas (1969)
Quadrula (s.s.) quadrula speciosa — Haas (1969)
Quadrula contrayensis — R.I. Johnson (1969)
Obliquaria quadrula — Burch (1975)
Quadrula rumphiana — Turgeon et al. (1988), Williams et al. (1993), Turgeon et al. (1998), Lydeard et al. (1999), ..., Williams et al. (2017), Inoue et al. (2018), Burlakova et al. (2019), Hauck et al. (2023)
Quadrula quedrula — Contreras-Arquieta (2000)
Quadrula fragosa — Watters et al. (2009)
Quadrula quadrula quadrula — ITIS (2012)
Q. quadrula — Sheng et al. (2014)