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Page last updated
Thu 3 September 2025

The Freshwater Mussels (Unionoida) of the World (and other less consequential bivalves)

FM(U)otW(aolcb) is the web version of the MUSSEL Project Database. Follow the links to browse the data or use the custom Google search field. Either way, you win!

Search the database pages:

Bivalvia | Unionoida | Unionoidea | Unionidae | Ambleminae | Lampsilini

genus Pachynaias Crosse & Fischer, 1894: synonymy
     1 Recent valid species (1 total species)

Pachynaias Fischer & Crosse, 1894
Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(15): 556.
(intro'd as sub-gen. of Unio Retzius, 1788)
Type species: Unio spheniopsis Morelet, 1849 (orig. desig.) = Pachynaias spheniopsis

Pavhynaias Contreras-Arquieta, 2000
Contreras-Arquieta, 2000. Mexicoa 2(1): 44.
(error for Pachynaias Fischer & Crosse, 1894)

Taxonomic History (since 1900)

Quadrula (sec. Pachynaias) — Simpson (1900), Simpson (1914)
Unio (Pleurobema) — Martens (1900)
Unio (Elliptio) — Martens (1900)
Nephronaias — Ihering (1901)
Plagiola (Arotonaias) — Simpson (1914)
Elliptio (Pachynaias) — Frierson (1927)
Elliptio (Barynaias) — Frierson (1927), Haas (1929)
Pachynaias — Haas (1929), Thiele (1934), Haas (1969), Haas (1969), Graf & Cummings (2007), ... Smith et al. (2020), Graf & Cummings (2021), Czaja et al. (2023), Freeman et al. (2025), Cummings et al. (2025)
Barynaias — Haas (1969)
Pavhynaias [sic] — Contreras-Arquieta (2000)

 
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