species Pachynaias spheniopsis (Morelet, 1849): synonymy

Unio spheniopsis Morelet, 1849

Morelet, 1849. Test. Nov. 1: 29.
Type(s): LECTOTYPE [AS HOLOTYPE] BMNH_93-2-4-2028 (by R.I. Johnson, 1971: 94), flumen Usumacinta, Guatemala.

Quadrula (sec. Pachynaias) spheniopsis — Simpson (1900), Simpson (1914)
Unio (Pleurobema) spheniopsis — Martens (1900)
Nephronaias spheniopsis — Ihering (1901)
Elliptio (Pachynaias) spheniopsis — Frierson (1927)
Pachynaias spheniopsis — Haas (1929), Thiele (1934), Haas (1969), Haas (1969), Graf & Cummings (2007), ... Graf & Cummings (2021), Czaja et al. (2023), Freeman et al. (2025), Cummings et al. (2025), Campbell & Lydeard (2026)
Pavhynaias [sic] spheniopsis — Contreras-Arquieta (2000)

Unio rugososulcatus Lea, 1866

Lea, 1866. Proc. Acad. Nat. Sci. 18: 33.
Lea, 1868. Jour. Acad. Nat. Sci. 6 [O. 12]: 266 [26], pl. 34, fig. 81.
Type(s): LECTOTYPE [AS HOLOTYPE] USNM_84392 (by R.I. Johnson, 1974: 127), Central America.

Quadrula (sec. Pachynaias) rugososulcata — Simpson (1900), Simpson (1914)
Elliptio (Pachynaias) rugososulcatus — Frierson (1927)
Pachynaias rugososulcata — Haas (1929), Haas (1969), Graf & Cummings (2021)
Pachynaias rugosulcata [sic] — Graf & Cummings (2007), Bogan (2010)
Pachynaias spheniopsis — Cummings et al. (2025)

Unio sallei var. grossus Martens, 1900

Martens, 1900. Biol. Centr.-Amer., Moll.: 517, pl. 34, figs. 2-2b.
(intro'd as intra-sp. of Unio sallei Crosse & Fischer, 1894)
Type(s): HOLOTYPE (MONOTYPY) ZMB_108850, Rio Salinas, Guatemala.

Unio (Elliptio) sallei var. grossus — Martens (1900)
Plagiola (Arotonaias) sallei var. grossa — Simpson (1914)
Elliptio (Barynaias) sallei-grossus — Frierson (1927)
Elliptio (Barynaias) sallei — Haas (1929)
Barynaias sallei — Haas (1969)
Pachynaias spheniopsis — Cummings et al. (2025)

Pachynaias rugosulcata Graf & Cummings, 2007

‘Lea’ Graf & Cummings, 2007. J. Moll. Studies 73: 309.
‘Lea’ Bogan, 2010. FADA: [24].
(error for Unio rugososulcatus Lea, 1866)