Larus

Larus is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere). Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls were placed in this genus, but this arrangement is now known to be polyphyletic, leading to the resurrection of the genera Ichthyaetus, Chroicocephalus, Leucophaeus, and Hydrocoloeus (this last had been recognized more often than the other genera) for several species traditionally included in Larus. They are in general medium to large birds, typically grey or white, often with black markings on their heads or wings. They have stout, longish bills and webbed feet. The taxonomy of the large gulls in the herring and lesser black-backed complex is very complicated, with different authorities recognising between two and eight species. 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 genus contains 25 species. 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 Larus elmorei (Early/Middle Pliocene of Bone Valley, southeastern U.S.) Larus lacus ( Late Pliocene of Pinecrest, southeastern U.S.) Larus perpetuus (Late Pliocene of Pinecrest, southeastern U.S.) Larus sp. (San Diego Late Pliocene of the southwestern U.S.) Larus oregonus (Late Pliocene - Late Pleistocene of the west-central U.