Great Hammerhead vs Green Sea Turtle

Sphyrna mokarran compared with Chelonia mydas

Key Differences

• Great Hammerhead is Critically Endangered while Green Sea Turtle is Endangered.
• Great Hammerhead is carnivore while Green Sea Turtle is herbivore.
• Great Hammerhead is 2.2x heavier than Green Sea Turtle.
• Green Sea Turtle lives longer (80 years vs 40 years).

Taxonomic Classification

Rank	Great Hammerhead	Green Sea Turtle
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Reptilia (Reptiles)
Order	Carcharhiniformes (Ground Sharks)	Testudines (Turtles & Tortoises)
Family	Sphyrnidae (Hammerhead Sharks)	Cheloniidae (Sea Turtles)
Genus	Sphyrna (Hammerhead Sharks)	Chelonia (Green Sea Turtles)
Species	Sphyrna mokarran	Chelonia mydas

Evolutionary Relationship

Great Hammerhead and Green Sea Turtle share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Great Hammerhead

CR — Critically Endangered

Trend: Decreasing ↓

Green Sea Turtle

EN — Endangered

Population: ~85.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Great Hammerhead	Green Sea Turtle
Diet	Carnivore	Herbivore
Average Lifespan	40 years	80 years
Average Length	5.0 m	1.2 m
Average Weight	450.0 kg	200.0 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.

Green Sea Turtle

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 8 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Australia, Brazil, Costa Rica, Indonesia, and Mexico. Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Green Sea Turtle

The green sea turtle is one of the largest sea turtles. They are named for the green color of their cartilage and fat, not their shells.