Larus

The genus Larus was introduced in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae. The genus name is from Ancient Greek laros (λάῥος) or Latin larus, which appears to have referred to a gull or other large seabird. The type species is the great black-backed gull (Larus marinus). The Latin name Larus marinus translates as "sea gull", and the gulls in this genus generally are the species most often known colloquially as "seagulls". Species The genus contains 25 extant species. }} }} }} }} }} }} }} }} }} Fossils Fossils of Larus gulls are known from the Middle Miocene, about 20-15 million years ago; allocation of earlier fossils to this genus is generally rejected. Biogeography of the fossil record suggests that the genus evolved in the northern Atlantic and spread globally during the Pliocene, when species diversity seems to have been highest, as with most seabirds. • Larus sp. (Middle Miocene of Grund, Austria) • Larus sp. (Middle Miocene of Romania) • Larus sp. (Late? Miocene/Early Pliocene of Lee Creek Mine, U.S.) - several species ==Ring species==

); 2. L. fuscus fuscus (North East European lesser black-backed gull); 3. L. fuscus heuglini (Heuglin's gull); 4. L. vegae birulai (Birula's gull); 5. L. vegae sensu stricto (Vega gull); 6. L. smithsonianus (American herring gull); 7. L. argentatus (European herring gull) The circumpolar group of Larus gull species has often been cited as a classic example of the ring species. The range of these gulls forms a ring around the North Pole. The European herring gull, which lives primarily in Great Britain and Northern Europe, can hybridize with the American herring gull (living in North America), which can also interbreed with the Vega or East Siberian gull, the western subspecies of which, Birula's gull, can hybridize with Heuglin's gull which, in turn, can interbreed with the Siberian lesser black-backed gull (all four of these live across the north of Siberia). The last is the eastern representative of the lesser black-backed gulls back in northwestern Europe, including Great Britain. However, the lesser black-backed gulls and herring gull are sufficiently different that they rarely interbreed; thus, the group of gulls forms a continuum except in Europe, where the two lineages meet. However, a recent genetic study has shown that this example is far more complicated than presented here, and probably does not constitute a true ring species. ==See also==