- Source: Leptoxis crassa
- Leptoxis crassa
- Leptoxis
- IUCN Red List of extinct species
- List of North American animals extinct in the Holocene
- List of recently extinct molluscs
- List of recently extinct invertebrates
- List of critically endangered invertebrates
- List of critically endangered molluscs
- IUCN Red List critically endangered species (Animalia)
- List of least concern molluscs
Athearnia crassa, the boulder snail, was a species of freshwater snail in the family Pleuroceridae. It was native to the United States, where it was known from Alabama, Georgia, Tennessee, and Virginia. It is now extinct.