Bigeye thresher vs Greater Crested Tern

Alopias pelagicus compared with Thalasseus bergii

Key Differences

• Bigeye thresher is Endangered while Greater Crested Tern is Least Concern.

Taxonomic Classification

Rank	Bigeye thresher	Greater Crested Tern
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Aves (Birds)
Order	Lamniformes (Mackerel Sharks)	Charadriiformes (Charadriiformes)
Family	Alopiidae	Laridae
Genus	Alopias	Thalasseus
Species	Alopias pelagicus	Thalasseus bergii

Evolutionary Relationship

Bigeye thresher and Greater Crested Tern share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Bigeye thresher

EN — Endangered

Greater Crested Tern

LC — Least Concern

Physical Characteristics

Attribute	Bigeye thresher	Greater Crested Tern
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Bigeye thresher

Habitat

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

Range

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

Greater Crested Tern

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Found in Norway.

Bigeye thresher

The Bigeye thresher (Alopias pelagicus) is a species in the genus Alopias. It is currently classified as Endangered on the IUCN Red List. Typically found in marine environments from coastal waters to deep ocean.