Alpine Rock-Cress vs common door snail

Arabis alpina compared with Clausilia bidentata

Taxonomic Classification

Rank	Alpine Rock-Cress	common door snail
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Mollusca (Mollusks)
Class	Magnoliopsida (Dicots)	Gastropoda (Gastropoda)
Order	Brassicales (Brassicales)	Stylommatophora (Stylommatophora)
Family	Brassicaceae	Clausiliidae
Genus	Arabis	Clausilia
Species	Arabis alpina	Clausilia bidentata

Conservation Status

Alpine Rock-Cress

LC — Least Concern

common door snail

LC — Least Concern

Physical Characteristics

Attribute	Alpine Rock-Cress	common door snail
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Alpine Rock-Cress

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Widely distributed across Europe (10 countries), North America (Canada, United States), and South America (Argentina).

common door snail

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Alpine Rock-Cress

The Alpine Rock-Cress (Arabis alpina) is a species in the genus Arabis. It is currently classified as Least Concern on the IUCN Red List. Typically found in diverse terrestrial habitats from tropical forests to temperate regions. Widely distributed across Europe (10 countries), North America (Canada, United States), and South America (Argentina).

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 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden