MUSSELpdb

Taxonomy

all genera

Summary

Species & Genus Richness of
freshwater mussels
by Taxonomy

Species & Genus Richness of
freshwater bivalves
by Family

Geography

Species Richness & Endemism of
freshwater mussels
by Geography

Data last updated
Mon 2 March 2026

nominal species Unio formosus Lea, 1831

Unio formosus Lea, 1831 = Epioblasma triquetra

specimen image from publication Lea, 1831. Trans. Amer. Phil. Soc. 4 [O. 1]: 111, pl. 16, fig. 41.

Taxonomic Opinions

+ Epioblasma triquetra (Rafinesque, 1820) — Watters et al., 2009: 116.

+ Epioblasma triquetra (Rafinesque, 1820) — Williams et al., 2008: 283.

+ Epioblasma triquetra (Rafinesque, 1820) — Parmalee & Bogan, 1998: 108.

+ Plagiola (Truncillopsis) triquetra (Rafinesque, 1820) — R.I. Johnson, 1978: 248.

+ Dysnomia triquetra (Rafinesque, 1820) — Burch, 1975: 163.

+ Dysnomia (Truncillopsis) triquetra (Rafinesque, 1820) — Haas, 1969: 479.

+ Dysnomia (Truncillopsis) triquetra (Rafinesque, 1820) — Frierson, 1927: 96.

+ Dysnomia (Truncillopsis) triquetra (Rafinesque, 1820) — Ortmann & Walker, 1922: 65.

+ Truncilla (s.s.) triquetra Rafinesque, 1820 — Simpson, 1914: 6.

+ Unio triangularis Barn. — de Gregorio, 1914: 40.

+ Truncilla (s.s.) triquetra Rafinesque — Simpson, 1900: 517.

+ Unio (s.s.) triangularis Barnes, 1823 — Call, 1900: 473.

+ Margaron (Unio) triangularis (Bar.) — Lea, 1870: 36.

+ Unio triangularis Barnes, 1823 — Sowerby, 1868: pl. 67, sp. 340.

+ Unio triqueter Raf. — Conrad, 1853: 259.

+ Unio (Truncilla) triqueter (Raf.) — Mørch, 1853: 44.

+ Truncilla triquetra Raf. — Agassiz, 1852: 44.

+ Margaron (Unio) triangularis (Bar.) — Lea, 1852: 23.

+ Unio triangularis Barnes — Hanley, 1843: 183.

+ Margarita (Unio) triangularis Bar. Eat. Hild. Say — Lea, 1838: 16.

+ Margarita (Unio) triangularis (Barnes, 1823) — Lea, 1836: 18.

+ Unio triqueter Raf. — Ferussac, 1835: 27.

= Unio formosus — Jay, 1835: 15.