''Crommium angustatum'' was a species of

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

in the family

Ampullinidae Ampullinidae are a mostly extinct taxonomic family of deep-water sea snails, marine gastropod molluscs in the clade Caenogastropoda.Bouchet, P. (2013). Ampullinidae. Accessed through: World Register of Marine Species at http://www.marinespecies.o ...

. Now extinct, it is known only from fossils. It came from the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

epoch. It was originally mistakenly identified as a

freshwater snail Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...

in the Ampullariidae family. It has been found in France.

References

Ampullinidae Gastropods described in 1828 Marine gastropods Fossil taxa described in 1828 Prehistoric gastropods {{Caenogastropoda-stub