Article · Wikipedia archive · Last revised Jun 14, 2026

Quadrula

Quadrula is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae native to rivers of the American Midwest and mid-south. All have thick nacreous shells with well-developed hinge teeth, many also with external shell sculpturing of nodules or lumps.

Last revised
Jun 14, 2026
Read time
≈ 1 min
Length
146 w
Citations
2
Source
Quadrula
Quadrula fragosa
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Unionida
Family: Unionidae
Tribe: Quadrulini
Genus: Quadrula
Rafinesque, 1820

Quadrula is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae native to rivers of the American Midwest and mid-south. All have thick nacreous shells with well-developed hinge teeth, many also with external shell sculpturing of nodules or lumps.

Species within the genus Quadrula

In 2012, many species classified as Quadrula were moved to Rotundaria and Theliderma based on genetic and morphological evidence.1 Species currently in Quadrula now consist of:2

Quadrula verrucosa source ↗
References

References

  1. Campbell, David; Lydeard, Charles (2012). "The Genera of Pleurobemini (Bivalvia: Unionidae: Ambleminae)". American Malacological Bulletin. 30 (1): 19–38. Bibcode:2012AMalB..30...19C. doi:10.4003/006.030.0102.
  2. Quadrula World Register of Marine Species