Quadrula
| Quadrula | |
|---|---|
| Quadrula fragosa | |
| Scientific classification | |
| Domain: | Eukaryota | 
| 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.