| Quadrula | |
|---|---|
| Quadrula intermedia | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Unionoida |
| Family: | Unionidae |
| Genus: | 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.