Common Seal vs Green Sea Turtle

Phoca vitulina compared with Chelonia mydas

Key Differences

• Common Seal is Near Threatened while Green Sea Turtle is Endangered.
• Common Seal is carnivore while Green Sea Turtle is herbivore.
• Green Sea Turtle is 2.5x heavier than Common Seal.
• Green Sea Turtle lives longer (80 years vs 30 years).

Taxonomic Classification

Rank	Common Seal	Green Sea Turtle
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Reptilia (Reptiles)
Order	Pinnipedia (Seals & Sea Lions)	Testudines (Turtles & Tortoises)
Family	Phocidae (True Seals)	Cheloniidae (Sea Turtles)
Genus	Phoca (Harbor Seals)	Chelonia (Green Sea Turtles)
Species	Phoca vitulina	Chelonia mydas

Evolutionary Relationship

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

Conservation Status

Common Seal

NT — Near Threatened

Population: ~500.0K

Trend: Stable →

Green Sea Turtle

EN — Endangered

Population: ~85.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common Seal	Green Sea Turtle
Diet	Carnivore	Herbivore
Average Lifespan	30 years	80 years
Average Length	1.7 m	1.2 m
Average Weight	80.0 kg	200.0 kg

Habitat & Geographic Range

Common Seal

Habitat

Typically found in diverse ecosystems where prey species are available.

Range

Found across Europe (7 countries) and North America (United States). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

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.

Common Seal

The most widely distributed pinniped, harbor seals inhabit temperate and subarctic coastal waters of both the North Atlantic and North Pacific. Adults reach up to 130 kg and spend roughly equal time at sea hunting fish, squid, and crustaceans and hauling out on beaches or rocks to rest. Their large, expressive eyes are adapted for underwater vision in low light. Harbor seals are a critical food source for orcas, sharks, and polar bears.

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.