''Thalasseus'', the crested terns, is a genus of eight species of

tern Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of e ...

s in the family

Laridae Laridae is a family of seabirds in the order Charadriiformes that includes the gulls, terns, skimmers and kittiwakes. It includes around 100 species arranged into 22 genera. They are an adaptable group of mostly aerial birds found worldwide. ...

. It has a worldwide distribution, and many of its species are abundant and well-known birds in their ranges. This genus had originally been created by

Friedrich Boie Friedrich Boie (4 June 1789 – 3 March 1870) was a German entomologist, herpetologist, ornithologist, and lawyer.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University ...

in 1822, but had been abandoned until a 2005 study confirmed the need for a separate genus for the crested terns. These large terns breed in very dense colonies on coasts and islands, and exceptionally inland on suitable large freshwater lakes close to the coast. They nest in a ground scrape. ''Thalasseus'' terns feed by plunge-diving for fish, almost invariably from the sea. They usually dive directly, and not from the "stepped-hover" favoured by, for example, the

Arctic tern The Arctic tern (''Sterna paradisaea'') is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south a ...

. The offering of fish by the male to the female is part of the courtship display. These species have long thin sharp bills, usually a shade of yellow or orange except in the

Sandwich tern The Sandwich tern (''Thalasseus sandvicensis'') is a tern in the family Laridae. It is very closely related to the lesser crested tern (''T. bengalensis''), Chinese crested tern (''T. bernsteini''), Cabot's tern (''T. acuflavidus''), and elegan ...

and Cabot's tern where the bills are black with yellow tips in most subspecies. All species have a shaggy crest. In winter, the ''Thalasseus'' terns' foreheads become white.

Taxonomy

The genus ''Thalasseus'' was erected by the German zoologist

in 1822. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

was subsequently designated as the

sandwich tern The Sandwich tern (''Thalasseus sandvicensis'') is a tern in the family Laridae. It is very closely related to the lesser crested tern (''T. bengalensis''), Chinese crested tern (''T. bernsteini''), Cabot's tern (''T. acuflavidus''), and elegan ...

(''Thalasseus sandvicensis''). The generic name is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

''Thalassa'' meaning "sea".

List of species

The genus contains eight species: An early

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

closely resembles a modern royal tern. It may be an unexpectedly early (3.7–4.8 million years before present) specimen of that species, or an ancestral member of the crested tern group.Olson, S., Rasmussen, P.C. "Miocene and Pliocene birds from the Lee Creek Mine, North Carolina" in Ray, C. E. & Bohaska, D.J. (2001). "Geology and Paleontology of the Lee Creek Mine, North Carolina, III." ''Smithsonian Contributions to Paleobiology'', 90: 233-365.

References

{{Taxonbar, from=Q133577 Bird genera