species Plectomerus dombeyanus (Valenciennes in Humboldt & Bonpland, 1827): synonymy

Unio crassidens Lamarck, 1819

(misidentified reference to Unio crassidens Lamarck, 1819)
Lister, 1685. Conch.: pl. 150, fig. 5.
Lamarck, 1819. Hist. Natur. Anim. sans Vert. 6: 71, sp. 3, var. a. [in part]

Quadrula (sec. Crenodonta) trapezoides — Simpson (1900), Simpson (1914)
Unio (s.s.) trapezoides — Call (1900)
Plectomerus trapezoides — Ortmann & Walker (1922)
Amblema (Plectomerus) dombeyana — Frierson (1927)
Plectomerus dombeyana — R.I. Johnson (1969), Oesch (1984)
Plectomerus dombeyanus — Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008)

Unio dombeyana Valenciennes, 1827

Valenciennes, 1827. Receuil Observ. Zool. 2(11-12): 227, pl. 53, figs. 1a-b.

Quadrula (sec. Crenodonta) trapezoides — Simpson (1900), Simpson (1914)
Plectomerus trapezoides — Ortmann & Walker (1922)
Amblema (Plectomerus) dombeyana — Frierson (1927), Haas (1969)
Amblema dombeyana — Thiele (1934)
Plectomerus dombeyanus — Haas (1969), Burch (1975), Gordon et al. (1979), R.I. Johnson (1980), Turgeon et al. (1988), ... de Moulpied et al. (2022), Hopper et al. (2023), Freeman et al. (2025), FMCS (2025), Campbell & Lydeard (2026)
Amblema dombeyanus — Davis & Fuller (1981)
Plectomerus dombeyana — Oesch (1984), Vidrine (1993)

Bariosta ponderosus Rafinesque, 1831

Rafinesque, 1831. Continuation: 2.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 73.

Bariosta ponderosus — Simpson (1914)
Plectomerus trapezoides — Ortmann & Walker (1922)
Amblema (Plectomerus) dombeyana — Frierson (1927)
Plectomerus dombeyanus — Burch (1975), Howells et al. (1996)
Plectomerus dombeyana — Oesch (1984)

Lasmigona ponderosa Rafinesque, 1831

Rafinesque, 1831. Continuation: 5.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 79.

Unio interruptus Say, 1831

(homonym of Unio (Eurynia) solenoides var. interrupta Rafinesque, 1820)
Say, 1831. Transylvania J. Med. Assoc. Sci. 4: 525.
Say, 1832. Amer. Conch. 4: pl. 33.

Quadrula (sec. Crenodonta) trapezoides — Simpson (1900), Simpson (1914)
Plectomerus trapezoides — Ortmann & Walker (1922)
Amblema (Plectomerus) dombeyana — Frierson (1927)
Plectomerus dombeyanus — Haas (1969), Burch (1975), Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008)
Plectomerus dombeyana — Oesch (1984)

Unio trapezoides Lea, 1831

Lea, 1831. Trans. Amer. Phil. Soc. 4 [O. 1]: 69 [79], pl. 3, fig. 1.
Type(s): FIGURED SYNTYPE USNM_84103, Lake St. Joseph, Mis.

Quadrula (sec. Crenodonta) trapezoides — Simpson (1900), Simpson (1914)
Unio (s.s.) trapezoides — Call (1900)
Quadrula trapezoides — Ortmann (1909)
Crenodonta trapezoides — Ortmann (1912)
Plectomerus trapezoides — Ortmann & Walker (1922)
Amblema (Plectomerus) dombeyana — Frierson (1927)
Plectomerus dombeyanus — Haas (1969), Burch (1975), R.I. Johnson (1980), Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008), Williams et al. (2014), Graf & Cummings (2021)
Plectomerus dombeyana — Oesch (1984), Vidrine (1993)

Unio dombeiana ‘Valenciennes’ of Authors

(error for Unio dombeyana Valenciennes, 1827)
‘Valenciennes’ of Authors.
Ferussac, 1835. Mag. Zool. 5(59-60): 27, 33.
Hanley, 1843. Illustr. Descr. Cat. Rec. Bivalve Shells: 175.

Quadrula trapezoides var. pentagonoides Frierson, 1902

(intro'd as intra-sp. of Unio trapezoides Lea, 1831)
Frierson, 1902. Nautilus 16(4): 39.
Frierson, 1927. Check List N. Amer. Naiades: 62 [as ‘A. (Plectomerus) dombeyana’].
Type(s): LECTOTYPE ANSP_128928 (by R.I. Johnson, 1972: 147), Lake Charles, La.

Quadrula (sec. Crenodonta) trapezoides var. pentagonoides — Simpson (1914)
Amblema (Plectomerus) dombeyana — Frierson (1927)
Plectomerus dombeyanus — Haas (1969), Parmalee & Bogan (1998)

Complanaria trapezius Agassiz, 1852

(error for Unio trapezoides Lea, 1831)
Agassiz, 1852. Arch. Naturg. 18(1): 49.