common door snail vs Polar bear

Clausilia bidentata compared with Ursus maritimus

Key Differences

• common door snail is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank	common door snail	Polar bear
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum	Mollusca (软体动物门)	Chordata (脊索动物门)
Class	Gastropoda (腹足纲)	Mammalia (哺乳動物)
Order	Stylommatophora (柄眼目)	Carnivora (食肉目)
Family	Clausiliidae	Ursidae (Bears)
Genus	Clausilia	Ursus (Bears)
Species	Clausilia bidentata	Ursus maritimus

Evolutionary Relationship

common door snail and Polar bear share a common ancestor at the Kingdom level: Animalia. (动物界)

Conservation Status

common door snail

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	common door snail	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

common door snail

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Polar bear

北极熊是地球上最大的陆地食肉动物，体重可超过700千克，分布于从加拿大到俄罗斯的北极海冰区。是高度特化的海洋哺乳动物，依赖海冰捕猎环斑海豹和髯海豹。是优秀的游泳者，能够横渡广阔的开阔水域。被列为易危种，因气候变化导致北极海冰迅速减少，种群正受到严重威胁。

Shared Countries

Both species can be found in 1 countries:

🇳🇴 Norway