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Gavia Howardae
''Gavia howardae'' is an extinct species of loon from the Piacenzian age from United States. Fossils of this bird were initially found in 1947 by Clifford Kennell in the San Diego Formation, California and were given a name in 1953 by Pierce Brodkorb. These first specimens consisted of humeri bones, which Brodkorb indicated based on the distal end of the humerus were a smaller species of the genus ''Gavia'', with a possible relationship with the pacific loon (''G. arctica''). More specimens were collected from the same deposits covering the entirety of the wing, some more complete than others. Chandler (1990) described and published these new materials and found ''G. howardae'' to be related to the red-throated loon (''G. stellata'') instead. Additional material has been recovered from the Yorktown Formation, North Carolina where in addition more wing bones, there were also remains of the leg and shoulder regions. Based on the overall size of the remains, ''G. howardae'' was on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loon
Loons (North American English) or divers ( British / Irish English) are a group of aquatic birds found in much of North America and northern Eurasia. All living species of loons are members of the genus ''Gavia'', family Gaviidae and order Gaviiformes . Description Loons, which are the size of large ducks or small geese, resemble these birds in shape when swimming. Like ducks and geese, but unlike coots (which are Rallidae) and grebes ( Podicipedidae), the loon's toes are connected by webbing. The loons may be confused with the cormorants (Phalacrocoracidae), but can be distinguished from them by their distinct call. Cormorants are not-too-distant relatives of loons, and like them are heavy-set birds whose bellies, unlike those of ducks and geese, are submerged when swimming. Loons in flight resemble plump geese with seagulls' wings that are relatively small in proportion to their bulky bodies. The bird points its head slightly upwards while swimming, but less so than cormor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piacenzian
The Piacenzian is in the international geologic time scale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 Ma and 2.588 ± 0.005 Ma (million years ago). The Piacenzian is after the Zanclean and is followed by the Gelasian (part of the Pleistocene). The Piacenzian is roughly coeval with the European land mammal age MN 16, overlaps the late Chapadmalalan and early Uquian South American land mammal age and falls inside the more extensive Blancan North American land mammal age. It also correlates with the Astian, Redonian, Reuverian and Romanian regional stages of Europe. Some authorities describe the British Red Crag Formation and Waltonian Stage as late Piacenzian, while others regard them as early Pleistocene. Carbon dioxide levels during the Piacenzian were similar to those of today, making this age, with global mean temperature 2–3 °C higher and sea levels about twenty meters higher than today, an important analogue for predictions of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Diego Formation
The San Diego Formation is a geologic formation in southwestern San Diego County in southern California (United States), and northwestern Baja California (México). Geology It is a coastal transitional marine and non-marine pebble and cobble conglomerate deposit and marine sandstone rock with marine fossils, from a former bay, deposited during the Middle Pliocene to Late Pliocene ages (2–3 million years ago), of the Pliocene period during the Cenozoic Era. This formation is found from the south side of Mount Soledad in San Diego County to Rosarito Beach in northern Baja California, including Tijuana, Mexico, and the southwestern corner of San Diego County from San Ysidro to Pacific Beach. San Diego Formation deposits were formed in a large, open, crescent-shaped bay similar in size to Monterey Bay that existed on the coast in Pliocene times. Aquifer The formation contains the San Diego Formation Basin, a large aquifer under Imperial Beach, Chula Vista, National City, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierce Brodkorb
William Pierce Brodkorb (September 29, 1908, Chicago – July 18, 1992, Gainesville, Florida) was an American ornithologist and paleontologist. Interested in birds since childhood, he was taught to prepare birds at the age of 16. Later, he received the opportunity to work as a staff technician in the Ornithology Division of the Field Museum. He entered the University of Michigan in 1933 and obtained his PhD degree in 1936. Subsequently, he became an assistant curator of birds at the Museum of Zoology in Michigan until 1946. In 1946, he accepted a professorate in the Department of Zoology at the University of Florida in Gainesville, a position he held until his retirement in 1989. His doctoral students include Glen E. Woolfenden. From the 1950s, Brodkorb built up a huge collection of bird fossils from the Miocene, the Pliocene, and the Pleistocene of Florida, which included 12,500 skeletons from 129 families, and is on display at the Florida Museum of Natural History, part of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Loon
The Pacific loon or Pacific diver (''Gavia pacifica''), is a medium-sized member of the loon, or diver, family. Taxonomy and etymology The Pacific loon, previously considered conspecific with the similar black-throated loon, was classified as a separate species in 1985. The genus name ''Gavia'' comes from the Latin for "sea mew", as used by ancient Roman naturalist Pliny the Elder. The specific epithet ''pacifica'' is Latin for the Pacific Ocean, the term meaning "peaceful". The phylogeny of this species is debated, with the black-throated loon and the Pacific loon traditionally being considered sister species, whereas a study using mitochondrial and nuclear intron DNA supported placing the black-throated loon sister to a clade consisting of the Pacific loon and the two sister species that are the common loon and the yellow-billed loon. In the former phylogeny, the split between the Pacific loon and the black-throated loon is proposed to have happened about 6.5 million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red-throated Loon The red-throated loon (North America) or red-throated diver (Britain and Ireland) (''Gavia stellata'') is a migratory aquatic bird found in the northern hemisphere. The most widely distributed member of the loon or diver family, it breeds primarily in Arctic regions, and winters in northern coastal waters. Ranging from in length, the red-throated loon is the smallest and lightest of the world's loons. In winter, it is a nondescript bird, greyish above fading to white below. During the breeding season, it acquires the distinctive reddish throat patch which is the basis for its common name. Fish form the bulk of its diet, though amphibians, invert |
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