Common hammerhead vs Laysan Duck

Sphyrna zygaena compared with Anas laysanensis

Key Differences

• Common hammerhead is Not Evaluated while Laysan Duck is Critically Endangered.

Taxonomic Classification

Rank	Common hammerhead	Laysan Duck
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Aves (Birds)
Order	Carcharhiniformes (Ground Sharks)	Anseriformes (Anseriformes)
Family	Sphyrnidae (Hammerhead Sharks)	Anatidae
Genus	Sphyrna (Hammerhead Sharks)	Anas
Species	Sphyrna zygaena	Anas laysanensis

Evolutionary Relationship

Common hammerhead and Laysan Duck share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Common hammerhead

NE — Not Evaluated

Laysan Duck

CR — Critically Endangered

Physical Characteristics

Attribute	Common hammerhead	Laysan Duck
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

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.

Laysan Duck

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and Mediterranean forests and woodlands within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Belgium, France, Netherlands, Norway, and United Kingdom. Currently classified as Critically Endangered 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.

Laysan Duck

Laysan Duck (Anas laysanensis) is classified as Critically Endangered (CR) on the IUCN Red List. Facing an extremely high risk of extinction in the wild due to severe population decline and habitat loss.