Onychoprion

Onychoprion
Sooty tern Onychoprion fuscatus
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Laridae
Subfamily: Sterninae
Genus: Onychoprion
Wagler, 1832
Type species
Sterna serrata
Species

Onychoprion lunatus
Onychoprion anaethetus
Onychoprion fuscatus
Onychoprion aleuticus

Onychoprion is a genus of four species of terns in the family Laridae. The genus name is from Ancient Greek onux, "claw" or "nail", and prion, "saw". As a group, they have been variously called "brown-winged terns" or "brown-backed terns", though only one species is actually brown; the other three are dark grey or black.