Common hammerhead vs Polar bear

Sphyrna zygaena compared with Ursus maritimus

Key Differences

• Common hammerhead is Not Evaluated while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Common hammerhead	Polar bear
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum same	Chordata (脊索动物门)	Chordata (脊索动物门)
Class	Chondrichthyes (软骨鱼纲)	Mammalia (哺乳動物)
Order	Carcharhiniformes (真鲨目)	Carnivora (食肉目)
Family	Sphyrnidae (Hammerhead Sharks)	Ursidae (Bears)
Genus	Sphyrna (Hammerhead Sharks)	Ursus (Bears)
Species	Sphyrna zygaena	Ursus maritimus

Evolutionary Relationship

Common hammerhead and Polar bear share a common ancestor at the Phylum level: Chordata. (脊索动物门)

Conservation Status

Common hammerhead

NE — Not Evaluated

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common hammerhead	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Common hammerhead

Habitat

Typically found in marine environments from coastal waters to deep ocean.

Range

Distributed across Chile, Denmark, Portugal, Sweden, and Taiwan.

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 hammerhead

The common hammerhead, <em>Sphyrna zygaena</em>, is a cartilaginous fish belonging to the order Carcharhiniformes, family Sphyrnidae. This species is typically found in marine environments and has a distribution that includes the waters of Chile, Denmark, Portugal, Sweden, and Taiwan, reflecting a wide range across both Atlantic and Pacific Ocean systems. As a hammerhead shark, <em>Sphyrna zygaena</em> possesses the characteristic cephalofoil, the laterally expanded head structure that provides enhanced sensory capabilities and hydrodynamic benefits. Hammerhead sharks are generally known to be active, wide-ranging predators within marine ecosystems. No dietary information has been provided for this specific species in current records. Biological traits of this species remain poorly documented in the 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。