Obliquaria (Sintoxia) sintoxia Rafinesque, 1820
Rafinesque, 1819, Jour. Phys. Chim. Hist. Nat. 88: 427 [as ‘U. (Obovaria) syntoxis’]. [nomen nudum]
Rafinesque, 1820, Ann. Gén. Sci. Phys. 5 (13): 310 [also as ‘U. sintoxia’].
Rafinesque, 1864, [in] Binney & Tryon, reprint: 29, 54.
(correct name for Unio (Obovaria) syntoxis Rafinesque, 1819)
Type(s): LECTOTYPE ANSP_20208, Ohio River.

Obliquaria (Sintoxia) sintoxia — Rafinesque (1820)
Unio sintoxia — Ferussac (1835), Conrad (1853)
Quadrula sintoxia — Vanatta (1915)
Fusconaia subrotunda — Ortmann & Walker (1922)
Quadrula (Fusconia) subrotunda — Frierson (1927)
Pleurobema sintoxia — Morrison (1969), Oesch (1984), Cummings & Mayer (1997), Parmalee & Bogan (1998), ..., FMCS (2021), Graf & Cummings (2021), Jeratthitikul et al. (2022), Hopper et al. (2023)
Obliquaria sintoxia — Burch (1975)
Pleurobema cordatum — R.I. Johnson (1980), Strayer & Jirka (1997)
Pleurobema (Sintoxia) sintoxia — Campbell & Lydeard (2012), Campbell & Lydeard (2012), Burlakova et al. (2012)

Unio coccineus Conrad, 1836
‘Hildreth’ Conrad, 1836, Monogr. Fam. Unionidae 1(3): 29, pl. 13, fig. 1.
‘Hildreth’ Conrad, 1853, Proc. Acad. Nat. Sci. 6: 247.
Type(s): FIGURED SYNTYPE USNM_85848, Columbus, Ohio.

Unio coccineus — Conrad (1836), Hanley (1843), Küster (1852), Conrad (1853)
Margarita (Unio) coccineus — Lea (1836), Lea (1838)
Margaron (Unio) coccineus — Lea (1852), Lea (1870)
Quadrula (sec. Fusconaia) coccinea — Simpson (1900), Simpson (1914)
Quadrula coccinea — Ortmann (1909), Ortmann (1909)
Pleurobema obliqua var. coccinea — Ortmann (1910)
Pleurobema coccineum — Ortmann (1912), Utterback (1915), F.C. Baker (1928), Turgeon et al. (1988), Cummings & Mayer (1992), Williams et al. (1993), Graf & Ó Foighil (2000), Graf (2002), ITIS (2012)
Pleurobema obliquum coccineum — Utterback (1915)
Pleurobema obliqua coccineum — Ortmann (1918)
Quadrula (Obliquata) coccinea — Frierson (1927)
Pleurobema cordatum coccineum — Murray & Leonard (1962), Gordon et al. (1979)
Quadrula (Obliquata) coccinea coccinea — Haas (1969)
Pleurobema cordatum — Mathiak (1979), R.I. Johnson (1980), Strayer & Jirka (1997)
Pleurobema cordatum f. coccineum — Mackie et al. (1980)
Pleurobema sintoxia — Oesch (1984), Turgeon et al. (1998), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), IUCN (2012), Zieritz et al. (2015)

Unio coccineus Lea, 1838
“Dr. Hildreth’s Letter” Lea, 1836, Synopsis Fam. Naiades: 34. [nomen nudum]
Lea, 1838, Trans. Amer. Phil. Soc. 6 [O. 2]: 12, pl. 5, fig. 12.
(homonym of Unio coccineus Conrad, 1836)
Type(s): FIGURED SYNTYPE USNM_85848, Columbus, Ohio.

Unio coccineus — Lea (1838), Hanley (1843), Conrad (1853), Reeve (1865), Sowerby (1868), B.H. Wright (1888), de Gregorio (1914)
Margarita (Unio) coccineus — Lea (1836), Lea (1838)
Margaron (Unio) coccineus — Lea (1852), Lea (1870)
Unio (Obovaria) coccineus — Mörch (1853), Adams & Adams (1857)
Quadrula (sec. Fusconaia) coccinea — Simpson (1900), Simpson (1914)
Unio (s.s.) coccineus — Call (1900)
Quadrula (Obliquata) catilla — Frierson (1927)
Pleurobema coccineum — F.C. Baker (1928), Graf & Cummings (2006), Hoeh et al. (2009)
Pleurobema cordatum — R.I. Johnson (1980)

Unio catillus Conrad, 1836
Conrad, 1836, Monogr. Fam. Unionidae 1(3): 30, pl. 13, fig. 2.
Conrad, 1853, Proc. Acad. Nat. Sci. 6: 246.

Unio catillus — Conrad (1836), Küster (1852), Conrad (1853)
Margarita (Unio) coccineus — Lea (1836), Lea (1838)
Unio coccineus — Hanley (1843), Reeve (1865), Sowerby (1868)
Margaron (Unio) coccineus — Lea (1852), Lea (1870)
Unio (Obovaria) coccineus — Mörch (1853)
Unio catilus — B.H. Wright (1888)
Quadrula (sec. Fusconaia) coccinea — Simpson (1900), Simpson (1914)
Pleurobema obliquum catillus — Utterback (1915)
Pleurobema catillus — Utterback (1915), Ortmann & Walker (1922)
Pleurobema obliqua catillus — Ortmann (1918)
Pleurobema cordatum catillus — Ortmann (1924), Ortmann (1925), Murray & Leonard (1962), Gordon et al. (1979)
Quadrula (Obliquata) catilla — Frierson (1927), Haas (1969)
Pleurobema coccineum catillus — F.C. Baker (1928)
Pleurobema cordatum — Burch (1975), R.I. Johnson (1980)
Pleurobema sintoxia — Oesch (1984), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Obliquaria (Scalenaria) triangularis Rafinesque, 1820
Rafinesque, 1820, Ann. Gén. Sci. Phys. 5 (13): 309 [also as ‘U. triangularis’].
Rafinesque, 1864, [in] Binney & Tryon, reprint: 53.

Obliquaria (Scalenaria) triangularis — Rafinesque (1820)
Unio triangularis — Ferussac (1835)
Fusconaia subrotunda — Ortmann & Walker (1922)
Quadrula (Obliquata) catilla — Frierson (1927)
Obliquaria triangularis — Burch (1975)

Unio (Obovaria) syntoxis Rafinesque, 1819
Rafinesque, 1819, Jour. Phys. Chim. Hist. Nat. 88: 427. [nomen nudum]
Rafinesque, 1864, [in] Binney & Tryon, reprint: 29.
(incorrect original spelling of Obliquaria (Sintoxia) sintoxia Rafinesque, 1820)

Unio (Obovaria) syntoxis — Rafinesque (1819)
Fusconaia subrotunda — Haas (1969)

Unio cuneus Conrad, 1838
Conrad, 1838, Monogr. Fam. Unionidae 2(11): back cover.
Conrad, 1840, Monogr. Fam. Unionidae 2(12): 105, pl. 58, fig. 1.
Type(s): HOLOTYPE (MONOTYPY) ANSP_41645, Arkansas River.

Unio cuneus — Conrad (1838), Conrad (1840), B.H. Wright (1888), Call (1895)
Margaron (Unio) coccineus — Lea (1852), Lea (1870)
Quadrula (sec. Fusconaia) cuneus — Simpson (1900), Simpson (1914)
Quadrula (Obliquata) coccinea-cunea — Frierson (1927)
Quadrula (Obliquata) coccinea cunea — Haas (1969)
Pleurobema cordatum — R.I. Johnson (1980)
Pleurobema pyramidatum — Vidrine (1993)
Pleurobema sintoxia — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Pleurobema missouriensis Marsh, 1901
Marsh, 1901, Nautilus 15(7): 74.
Walker, 1915, Nautilus 28(12): 140, pl. 5, figs. 1-2.
Type(s): FIGURED SYNTYPE UMMZ_113527, Black River, Poplar Bluff, Butler Co., Missouri.

Pleurobema missouriensis — Marsh (1901)
Pleurobema (s.s.) missouriense — Simpson (1914)
Pleurobema missourense — Utterback (1915)
Quadrula (Obliquata) missouriensis — Frierson (1927), Haas (1969)
Fusconaia subrotunda — R.I. Johnson (1980)
Pleurobema sintoxia — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Quadrula (sec. Fusconaia) coccinea var. magnalacustris Simpson, 1914
Simpson, 1914, Descr. Cat. Naiades: 884.
(intro'd as intra-sp. of Unio coccineus Conrad, 1836; new name for Quadrula (sec. Fusconaia) coccinea var. paupercula Simpson, 1900)
Type(s): LECTOTYPE USNM_133834, Niagara Riv., 3 mi above Falls.

Quadrula (sec. Fusconaia) coccinea var. magnalacustris — Simpson (1914)
Pleurobema coccineum paupercula — Ortmann & Walker (1922)
Quadrula (Obliquata) coccinea-magnalacustris — Frierson (1927)
Quadrula (Obliquata) coccinea magnalacustris — Haas (1969)
Pleurobema cordatum — R.I. Johnson (1980)
Pleurobema sintoxia — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Obliquaria (Scalenaria) triangularis var. nigrescens Rafinesque, 1820
Rafinesque, 1820, Ann. Gén. Sci. Phys. 5 (13): 309.
Rafinesque, 1864, [in] Binney & Tryon, reprint: 53.
(intro'd as intra-sp. of Obliquaria (Scalenaria) triangularis Rafinesque, 1820)

Obliquaria (Scalenaria) triangularis var. nigrescens — Rafinesque (1820)

Unio solidus Lea, 1838
Lea, 1836, Synopsis Fam. Naiades: 20. [nomen nudum]
Lea, 1838, Trans. Amer. Phil. Soc. 6 [O. 2]: 13, pl. 5, fig. 13.

Unio solidus — Lea (1838), Hanley (1843), Küster (1862), Reeve (1865), B.H. Wright (1888)
Margarita (Unio) solidus — Lea (1836), Lea (1838)
Margaron (Unio) solidus — Lea (1852), Lea (1870)
Unio obovalis — Conrad (1853)
Unio (Lampsilis) solidus — Adams & Adams (1857)
Quadrula (sec. Fusconaia) solida — Simpson (1900), Simpson (1914)
Unio (s.s.) solidus — Call (1900)
Pleurobema obliquum catillus — Utterback (1915)
Pleurobema catillus — Utterback (1915), Ortmann & Walker (1922)
Pleurobema obliqua catillus — Ortmann (1918)
Pleurobema cordatum catillus — Ortmann (1925), Murray & Leonard (1962)
Quadrula (Obliquata) catilla — Frierson (1927), Haas (1969)
Pleurobema coccineum solida — F.C. Baker (1928)
Pleurobema sintoxia — Morrison (1969), Oesch (1984), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)
Pleurobema cordatum — Burch (1975), R.I. Johnson (1980), Strayer & Jirka (1997)

Unio cardiacea Deshayes, 1839
‘Guérin’ Deshayes, 1839, Traité Élém. Conchyl.: 19, pl. 31, figs. 1-2.
(misidentified reference to Unio cardiacea Guérin-Méneville, 1823)

Unio cardiacea — Deshayes (1839)
Margaron (Unio) pyramidatus — Lea (1852), Lea (1870)
Quadrula (sec. Fusconaia) solida — Simpson (1900), Simpson (1914)
Quadrula (Obliquata) catilla — Haas (1969)
Pleurobema sintoxia — Parmalee & Bogan (1998), Watters et al. (2009)

Unio gouldianus Jay, 1839
Ward in Jay, 1839, Cat. Rec. Shells: 24. [nomen nudum]

Unio gouldianus — Jay (1839)
Margaron (Unio) ebenus — Lea (1852)
Quadrula (sec. Fusconaia) coccinea — Simpson (1900), Simpson (1914)
Unio (s.s.) coccineus — Call (1900)
Quadrula (Fusconia) antrosa — Frierson (1927)
Fusconaia antrosa — Haas (1969)
Pleurobema cordatum — R.I. Johnson (1980)
Pleurobema sintoxia — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio fulgidus Lea, 1845
Lea, 1845, Proc. Amer. Phil. Soc. 4: 164.
Lea, 1848, Trans. Amer. Phil. Soc. 10 [O. 4]: 73 [47], pl. 4, fig. 10.
Type(s): FIGURED SYNTYPE USNM_84649, Alexandria, La.

Unio fulgidus — Lea (1845), Conrad (1853), B.H. Wright (1888)
Margaron (Unio) fulgidus — Lea (1852), Lea (1870)
Unio (Lampsilis) fulgidus — Adams & Adams (1857)
Quadrula (sec. Fusconaia) solida — Simpson (1900), Simpson (1914)
Pleurobema catillus — Utterback (1915)
Quadrula (Obliquata) catilla — Frierson (1927), Haas (1969)
Pleurobema cordatum — R.I. Johnson (1980)
Pleurobema sintoxia — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio obovalis Conrad, 1853
‘Rafinesque’ Conrad, 1853, Proc. Acad. Nat. Sci. 6: 253.
(misidentified reference to Obovaria obovalis Rafinesque, 1820)

Unio obovalis — Conrad (1853)
Quadrula (sec. Fusconaia) solida — Simpson (1900), Simpson (1914)
Pleurobema sintoxia — Parmalee & Bogan (1998), Watters et al. (2009)

Unio mytiloides Lapham, 1860
‘Raf.’ Lapham, 1860, Proc. Acad. Nat. Sci. 12: 156.
(misidentified reference to Pleurobema mytiloides Rafinesque, 1820)

Unio mytiloides — Lapham (1860)
Pleurobema coccineum catillus — F.C. Baker (1928)

Unio obliquus Lapham, 1860
‘Lamarck’ of Authors.
Lapham, 1860, Proc. Acad. Nat. Sci. 12: 156.
Baker, 1905, Trans. Acad. Sci. St. Louis 15: 256.
Ortmann, 1919, Mem. Carnegie Mus. 8(1): 73. [in part]
(misidentified reference to Unio obliqua Lamarck, 1819)

Unio obliquus — Lapham (1860)
Pleurobema coccineum solida — F.C. Baker (1928)

Unio pyramidatus Call, 1885
Call, 1885, unknown publication: 46.
(misidentified reference to Unio pyramidatus Lea, 1831)

Unio pyramidatus — Call (1885)
Pleurobema coccineum catillus — F.C. Baker (1928)

Unio catilus B.H. Wright, 1888
‘Conrad’ of Authors.
B.H. Wright, 1888, Check List N. Amer. Unionidae etc.: [2].
Ortmann, 1924, Amer. Midl. Nat. 9(1): 38.
(error for Unio catillus Conrad, 1836)

Unio catilus — B.H. Wright (1888)
Quadrula (sec. Fusconaia) coccinea — Simpson (1900), Simpson (1914)
Pleurobema sintoxia — Parmalee & Bogan (1998), Watters et al. (2009)

Unio cuneus Call, 1895
Call, 1895, Trans. Acad. Sci. St. Louis 7: 14.
(reference to Unio cuneus Conrad, 1838)

Unio cuneus — Call (1895)
Quadrula (sec. Fusconaia) coccinea — Simpson (1900), Simpson (1914)

Quadrula kirtlandiana Simpson, 1900
‘Conrad’ Simpson, 1900, Proc. U.S. Nat. Mus. 22: 791. [in part]
‘Conrad’ Simpson, 1914, Descr. Cat. Naiades: 891. [in part]
(misidentified reference to Unio kirtlandianus Lea, 1834)

Quadrula kirtlandiana — Simpson (1900)
Pleurobema coccineum — F.C. Baker (1928)

Quadrula pyramidata Simpson, 1900
‘Lea’ Simpson, 1900, Proc. U.S. Nat. Mus. 22: 789. [in part]
Chadwick, 1906, unknown publication: 97.
‘Lea’ Simpson, 1914, Descr. Cat. Naiades: 889. [in part]
(misidentified reference to Unio pyramidatus Lea, 1831)

Quadrula pyramidata — Simpson (1900)
Pleurobema coccineum solida — F.C. Baker (1928)

Quadrula (sec. Fusconaia) coccinea var. paupercula Simpson, 1900
Simpson, 1900, Proc. U.S. Nat. Mus. 22: 789.
(intro'd as intra-sp. of Unio coccineus Conrad, 1836; homonym of Unio pauperculus Lea, 1861; renamed Quadrula (sec. Fusconaia) coccinea var. magnalacustris Simpson, 1914)

Quadrula (sec. Fusconaia) coccinea var. paupercula — Simpson (1900)
Quadrula (sec. Fusconaia) coccinea var. magnalacustris — Simpson (1914)
Pleurobema coccineum paupercula — Ortmann & Walker (1922)
Quadrula (Obliquata) coccinea-magnalacustris — Frierson (1927)
Quadrula (Obliquata) coccinea magnalacustris — Haas (1969)
Pleurobema cordatum — R.I. Johnson (1980), Strayer & Jirka (1997)
Pleurobema sintoxia — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), IUCN (2012)

Pleurobema missourense Utterback, 1915
‘Marsh’ Utterback, 1915, Amer. Midl. Nat. 4(5): 195.
(error for Pleurobema missouriensis Marsh, 1901)

Pleurobema missourense — Utterback (1915)

Pleurobema coccineum var. mississippiensis F.C. Baker, 1928
F.C. Baker, 1928, Bull. Wisconsin Geol. Nat. Hist. Survey 70(2): 121, pl. 53, figs. 1-5.
(intro'd as intra-sp. of Unio coccineus Conrad, 1836)
Type(s): HOLOTYPE (ORIG. DESIG.) INHS_82273, Lake Pepin, Wisconsin.

Pleurobema coccineum var. mississippiensis — F.C. Baker (1928)
Pleurobema coccineum mississippiensis — F.C. Baker (1928)
Pleurobema cordatum — R.I. Johnson (1980)
Pleurobema sintoxia — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Taxonomic History (since 1900)

Quadrula (sec. Fusconaia) coccinea — Simpson (1900), Simpson (1914)
Unio (s.s.) coccineus — Call (1900)
Quadrula (sec. Fusconaia) cuneus — Simpson (1900), Simpson (1914)
Quadrula (sec. Fusconaia) solida — Simpson (1900), Simpson (1914)
Unio (s.s.) solidus — Call (1900)
Quadrula kirtlandiana — Simpson (1900)
Quadrula pyramidata — Simpson (1900)
Quadrula (sec. Fusconaia) coccinea var. paupercula — Simpson (1900)
Pleurobema missouriensis — Marsh (1901)
Quadrula coccinea — Ortmann (1909), Ortmann (1909)
Pleurobema obliqua var. coccinea — Ortmann (1910)
Pleurobema coccineum — Ortmann (1912), Utterback (1915), F.C. Baker (1928), Turgeon et al. (1988), ..., Graf (2002), Graf & Cummings (2006), Hoeh et al. (2009), ITIS (2012)
Unio coccineus — de Gregorio (1914)
Quadrula (sec. Fusconaia) coccinea var. magnalacustris — Simpson (1914)
Pleurobema (s.s.) missouriense — Simpson (1914)
Quadrula sintoxia — Vanatta (1915)
Pleurobema obliquum catillus — Utterback (1915)
Pleurobema catillus — Utterback (1915), Ortmann & Walker (1922)
Pleurobema obliquum coccineum — Utterback (1915)
Pleurobema missourense — Utterback (1915)
Pleurobema obliqua catillus — Ortmann (1918)
Pleurobema obliqua coccineum — Ortmann (1918)
Fusconaia subrotunda — Ortmann & Walker (1922), Haas (1969), R.I. Johnson (1980)
Pleurobema coccineum paupercula — Ortmann & Walker (1922)
Pleurobema cordatum catillus — Ortmann (1924), Ortmann (1925), Murray & Leonard (1962), Gordon et al. (1979)
Quadrula (Obliquata) catilla — Frierson (1927), Haas (1969)
Quadrula (Fusconia) subrotunda — Frierson (1927)
Quadrula (Obliquata) coccinea — Frierson (1927)
Quadrula (Obliquata) coccinea-cunea — Frierson (1927)
Quadrula (Fusconia) antrosa — Frierson (1927)
Quadrula (Obliquata) coccinea-magnalacustris — Frierson (1927)
Quadrula (Obliquata) missouriensis — Frierson (1927), Haas (1969)
Pleurobema coccineum catillus — F.C. Baker (1928)
Pleurobema coccineum solida — F.C. Baker (1928)
Pleurobema coccineum var. mississippiensis — F.C. Baker (1928)
Pleurobema coccineum mississippiensis — F.C. Baker (1928)
Pleurobema cordatum coccineum — Murray & Leonard (1962), Gordon et al. (1979)
Pleurobema sintoxia — Morrison (1969), Oesch (1984), Cummings & Mayer (1997), Parmalee & Bogan (1998), ..., FMCS (2021), Graf & Cummings (2021), Jeratthitikul et al. (2022), Hopper et al. (2023)
Quadrula (Obliquata) coccinea coccinea — Haas (1969)
Quadrula (Obliquata) coccinea cunea — Haas (1969)
Fusconaia antrosa — Haas (1969)
Quadrula (Obliquata) coccinea magnalacustris — Haas (1969)
Obliquaria triangularis — Burch (1975)
Obliquaria sintoxia — Burch (1975)
Pleurobema cordatum — Burch (1975), Mathiak (1979), R.I. Johnson (1980), Strayer & Jirka (1997)
Pleurobema cordatum f. coccineum — Mackie et al. (1980)
Pleurobema pyramidatum — Vidrine (1993)
Pleurobema (Sintoxia) sintoxia — Campbell & Lydeard (2012), Campbell & Lydeard (2012), Burlakova et al. (2012)