common whorl snail vs koala

Vertigo pygmaea compared with Phascolarctos cinereus

Key Differences

common whorl snail is Near Threatened while koala is Vulnerable.

Taxonomic Classification

Rank	common whorl snail	koala
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Mollusca (軟体動物)	Chordata (脊索動物)
Class	Gastropoda (腹足綱)	Mammalia (哺乳類)
Order	Stylommatophora (Stylommatophora)	Diprotodontia (カンガルー目)
Family	Vertiginidae	Phascolarctidae (Koalas)
Genus	Vertigo	Phascolarctos (Koalas)
Species	Vertigo pygmaea	Phascolarctos cinereus

Evolutionary Relationship

common whorl snail and koala share a common ancestor at the Kingdom level: Animalia. (動物)

表示 Kingdom: Animalia

Conservation Status

common whorl snail

NT — Near Threatened

koala

VU — Vulnerable

Population: ~100.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	common whorl snail	koala
Diet	—	Herbivore
Average Lifespan	—	15 years
Average Length	—	75 cm
Average Weight	—	10.0 kg

Habitat & Geographic Range

common whorl snail

Habitat

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

Range

Found across Europe (9 countries) and North America (United States). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

koala

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

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

common whorl snail

Vertigo pygmaea, commonly known as the common whorl snail, is a minute land snail in the family Vertiginidae, listed as Near Threatened on the IUCN Red List, reflecting documented population declines attributable to habitat loss, agricultural intensification, and wetland drainage across its European and North American range. The species occurs across much of Europe and parts of the United States, typically inhabiting short-sward calcareous grasslands, chalk and limestone downlands, damp meadows, and the bases of grassy slopes where the vegetation structure is open and low-growing. Vertigo pygmaea is among the smallest terrestrial mollusks, with a shell typically measuring only 1.5–2 mm in height — a feature shared by all members of the genus Vertigo. Despite its tiny size, the shell is complex, with multiple internal tooth-like lamellae visible within the aperture that are used in species identification. The species typically feeds on decaying plant material, algae, and fungi associated with soil and leaf litter microhabitats. It requires specific microhabitat conditions including moderate soil moisture and an abundance of calcium for shell formation. Biological traits including average lifespan, precise shell dimensions, and mass remain poorly documented in standardized databases. Conservation efforts for Vertigo pygmaea typically focus on maintaining and restoring calcareous grassland habitats through appropriate grazing management regimes.

koala

オーストラリア東部・南東部を代表する有袋類で、体重は最大15kgに達し、低カロリーのユーカリの葉食から得るエネルギーを節約するために1日最大22時間を睡眠に費やす。他の哺乳類の多くを死に至らしめる有毒なユーカリ成分を処理するために高度に特化しており、解毒に特別に適応した腸内微生物叢を持つ。クラミジア感染症、生息地の伐採、気候変動により個体数が激減し、2022年に絶滅危惧種に指定された。