Great Hammerhead vs Irrawaddy dolphin

Sphyrna mokarran compared with Orcaella brevirostris

Key Differences

• Great Hammerhead is Critically Endangered while Irrawaddy dolphin is Endangered.

Taxonomic Classification

Rank	Great Hammerhead	Irrawaddy dolphin
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Mammalia (Mammals)
Order	Carcharhiniformes (Ground Sharks)	Cetacea (Whales & Dolphins)
Family	Sphyrnidae (Hammerhead Sharks)	Delphinidae (Oceanic Dolphins)
Genus	Sphyrna (Hammerhead Sharks)	Orcaella
Species	Sphyrna mokarran	Orcaella brevirostris

Evolutionary Relationship

Great Hammerhead and Irrawaddy dolphin share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Great Hammerhead

CR — Critically Endangered

Trend: Decreasing ↓

Irrawaddy dolphin

EN — Endangered

Physical Characteristics

Attribute	Great Hammerhead	Irrawaddy dolphin
Diet	Carnivore	—
Average Lifespan	40 years	—
Average Length	5.0 m	—
Average Weight	450.0 kg	—

Habitat & Geographic Range

Great Hammerhead

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and flooded grasslands and savannas, among 5 distinct biome types spanning the Indomalayan and Neotropic and Oceanian realms. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Colombia, Taiwan, and Venezuela. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Irrawaddy dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Great Hammerhead

The largest hammerhead shark species, great hammerheads reach up to 6 meters and are found in tropical and subtropical coastal waters worldwide. Their distinctive T-shaped head (cephalofoil) dramatically increases sensory surface area for electroreception, enabling them to detect buried stingrays through sand with exceptional precision — stingrays are a preferred prey. Critically Endangered, with populations declining dramatically due to highly valued fins and bycatch mortality.