Atlantic Ancula vs common door snail

Ancula gibbosa compared with Clausilia bidentata

Taxonomic Classification

Rank	Atlantic Ancula	common door snail
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Mollusca (Mollusks)	Mollusca (Mollusks)
Class same	Gastropoda (Gastropoda)	Gastropoda (Gastropoda)
Order	Nudibranchia (Nudibranchia)	Stylommatophora (Stylommatophora)
Family	Goniodorididae	Clausiliidae
Genus	Ancula	Clausilia
Species	Ancula gibbosa	Clausilia bidentata

Evolutionary Relationship

Atlantic Ancula and common door snail share a common ancestor at the Class level: Gastropoda. (Gastropoda)

Conservation Status

Atlantic Ancula

LC — Least Concern

common door snail

LC — Least Concern

Physical Characteristics

Attribute	Atlantic Ancula	common door snail
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Atlantic Ancula

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Distributed across Denmark, Norway, and Sweden.

common door snail

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Atlantic Ancula

The Atlantic Ancula (Ancula gibbosa) is a species in the genus Ancula. It is currently classified as Least Concern on the IUCN Red List. Typically found in terrestrial and aquatic habitats including forests and freshwater.

common door snail

<em>Clausilia bidentata</em>, the common door snail, is a terrestrial gastropod mollusk in the family Clausiliidae. This species is distributed across Belgium, Denmark, Norway, and Sweden, where it typically inhabits moist terrestrial environments including deciduous woodlands, rocky slopes, hedgerows, and the margins of freshwater habitats. The common door snail is recognized by its elongated, sinistral (left-handed) shell, which is a distinctive trait of the family Clausiliidae. The shell is typically brown to gray and reaches approximately 12–15 millimeters in length. <em>Clausilia bidentata</em> generally feeds on algae, lichens, fungi, and decaying plant material by rasping food with a radula. It often shelters under bark, stones, and leaf litter during dry or cold conditions. Like many clausiliids, it possesses a complex internal shell structure called a clausilium that closes the shell aperture to reduce desiccation. The species is assessed as Least Concern, reflecting stable populations across its European range. Detailed biological traits beyond those noted here are not extensively documented in the current scientific literature.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden