| Longnut | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Unionida |
| Family: | Unionidae |
| Genus: | Pleurobema |
| Species: | †P. nucleopsis |
| Binomial name | |
| †Pleurobema nucleopsis (Conrad, 1849) | |
The longnut (Pleurobema nucleopsis) was a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
This species was endemic to the United States. Its natural habitat was rivers.
