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Podiceps Oligoceanus
''Podiceps oligoceanus'' is an extinct species of grebe possibly from the Neogene period which the specimen has been found in the United States. History The species was part of a major paper that was commissioned by professor Charles Schuchert in 1914 in which he had Robert Wilson Shufeldt for revision of the type specimens of fossil birds that were described by Othniel Charles Marsh for the Peabody Museum of Natural History. Description The femur of the holotype ( YPM 983) is similar to grebes of the genus ''Aechmophorus'' and the red-necked grebe (''P. grisegena''), though the shaft is slender and heavier. Classification Initially the species was placed in the now defunct genus '' Colymbus'' by Shufeldt (1915) (''Colymbus oligoceanus''), it has since been reclassified into the genus ''Podiceps''. Paleobiology The holotype femur was found at the John Day Fossil Beds National Monument. The age of ''P. oligoceanus'' is uncertain. Shufeldt (1915) tentatively assign the species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Wilson Shufeldt
Robert Wilson Shufeldt Jr. (December 1, 1850January 21, 1934) was an American osteologist, myologist, museologist and ethnographer who contributed to comparative studies of bird anatomy and forensic science. He hated black people, strongly approved of the Ku Klux Klan, and was a proponent of white supremacy. A scandal and subsequent divorce from his second wife, the granddaughter of the famous ornithologist John James Audubon, led to a landmark judgment by the Supreme Court of the United States of America on the subject of alimony and bankruptcy. Life and career Son of Admiral Robert Wilson Shufeldt and Sarah Shufeldt, he was born in New York in 1850. After a school education in the United States and Havana, he joined as a Captain's clerk on the US Gunboat which was under the command of his father. In 1872 he joined Cornell University to study medicine and obtained a degree in 1876 from Columbian, Washington, D.C. He joined the Medical Department of the Army as a Lieuten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colymbus
The common loon or great northern diver (''Gavia immer'') is a large member of the loon, or diver, family of birds. Breeding adults have a plumage that includes a broad black head and neck with a greenish, purplish, or bluish sheen, blackish or blackish-grey upperparts, and pure white underparts except some black on the undertail coverts and vent. Non-breeding adults are brownish with a dark neck and head marked with dark grey-brown. Their upperparts are dark brownish-grey with an unclear pattern of squares on the shoulders, and the underparts, lower face, chin, and throat are whitish. The sexes look alike, though males are significantly heavier than females. During the breeding season, loons live on lakes and other waterways in Canada, the northern United States (including Alaska), and southern parts of Greenland and Iceland. Small numbers breed on Svalbard and sporadically elsewhere in Arctic Eurasia. Common loons winter on both coasts of the US as far south as Mexico, and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold Glacial period, glacial periods and warmer Interglacial, int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to 15.97 ± 0.05 Ma (million years ago). It was preceded by the Oligocene epoch. As the climate started to get cooler, the landscape started to change. New mammals evolved to replace the extinct animals of the Oligocene epoch. The first members of the hyena and weasel family started to evolve to replace the extinct ''Hyaenodon'', entelodonts and bear-dogs. The chalicotheres survived the Oligocene epoch. A new genus of entelodont called ''Daeodon'' evolved in order to adapt to the new habitats and hunt the new prey animals of the Early Miocene epoch; it quickly became the top predator of North America. But it became extinct due to competition from ''Amphicyon'', a newcomer from Eurasia. ''Amphicyon'' bested ''Daeodon'' because the bear-dog's la ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from Ancient Greek (''olígos'') 'few' and (''kainós'') 'new', and refers to the sparsity of Neontology, extant forms of Mollusca, molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Day Fossil Beds National Monument
John Day Fossil Beds National Monument is a U.S. national monument in Wheeler and Grant counties in east-central Oregon. Located within the John Day River basin and managed by the National Park Service, the park is known for its well-preserved layers of fossil plants and mammals that lived in the region between the late Eocene, about 45 million years ago, and the late Miocene, about 5 million years ago. The monument consists of three geographically separate units: Sheep Rock, Painted Hills, and Clarno. The units cover a total of of semi-desert shrublands, riparian zones, and colorful badlands. About 210,000 people visited the park in 2016 to engage in outdoor recreation or to visit the Thomas Condon Paleontology Center or the James Cant Ranch Historic District. Before the arrival of Euro-Americans in the 19th century, the John Day basin was frequented by Sahaptin people who hunted, fished, and gathered roots and berries in the region. After road-building ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Podiceps
''Podiceps'' is a genus of birds in the grebe family. The genus name comes from Latin , "rear-end" and ', "foot", and is a reference to the placement of a grebe's legs towards the rear of its body. It has representatives breeding in all continents except Antarctica. Some species are partially or entirely migratory, moving in winter to the coast or warmer climates. Most species are widespread and overall common, but three South American species each are restricted to a single country; two of them are seriously threatened and a third is already extinct. They breed in vegetated areas of freshwater lakes, nesting on the water's edge, since their legs are set too far back for easy walking. Usually two eggs are laid, and the striped young may be carried on the adult's back. All the genus are excellent swimmers and divers, and pursue their fish prey underwater. Adults have striking breeding plumage, with no difference between the sexes. In winter, the plumage is subdued whites and gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red-necked Grebe
The red-necked grebe (''Podiceps grisegena'') is a migratory aquatic bird found in the temperate regions of the northern hemisphere. Its wintering habitat is largely restricted to calm waters just beyond the waves around ocean coasts, although some birds may winter on large lakes. Grebes prefer shallow bodies of fresh water such as lakes, marshes or fish-ponds as breeding sites. The red-necked grebe is a fairly drab dusky-grey bird in winter. During the breeding season, it acquires the distinctive red neck plumage, black cap and contrasting pale grey face from which its name was derived. It also has an elaborate courtship display and a variety of loud mating calls. Once paired, it builds a nest from water plants on top of floating vegetation in a shallow lake or bog. Like all grebes, the red-necked is a good swimmer and particularly swift diver, and responds to danger by diving rather than flying. The feet are positioned far back on the body, near the tail, which makes the bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grebe
Grebes () are aquatic diving birds in the order (biology), order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Most grebes fly, although some flightless species exist, most notably in stable lakes. The order contains a single family (biology), family, the Podicipedidae, which includes 22 species in six extant genus, genera. Although, superficially, they resemble other diving birds such as loons and coots, they are most closely related to flamingos, as supported by morphology (biology), morphological, molecular and paleontology, paleontological data. Many species are monogamy in animals, monogamous and are known for their courtship displays, with the pair performing synchronized dances across the water's surface. The birds build floating vegetative nests where they lay several eggs. About a third of the world's grebes are listed at various levels of conservatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aechmophorus
''Aechmophorus'' is a genus of birds in the grebe family. Species It has two living representatives breeding in western North America. One prehistoric species has been described from fossil remains: *'' Aechmophorus elasson'' (Late Pliocene of W USA) Although the two living species look very similar, bill shape and coloration, as well as feathering around the scarlet eye of the bird can be used to determine the precise species. Distinguishing features The western grebe has a straight bill with a dull green-yellow color as opposed to the Clark's grebe, which has a slightly upturned, bright orange-yellow bill. In both species the male has a longer and deeper bill than that of the female, making it a distinguishing feature. All species of grebes display the pattern of lobed feet. A tough skin surrounds each toe separately, providing more surface area for effective swimming. This form increases the power of propulsion per stroke and reduces drag when the bird is recovering. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur
The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femoral head, top of the femur fits into a socket in the pelvis called the hip joint, and the bottom of the femur connects to the shinbone (tibia) and kneecap (patella) to form the knee. In humans the femur is the largest and thickest bone in the body. Structure The femur is the only bone in the upper Human leg, leg. The two femurs converge Anatomical terms of location, medially toward the knees, where they articulate with the Anatomical terms of location, proximal ends of the tibiae. The angle at which the femora converge is an important factor in determining the femoral-tibial angle. In females, thicker pelvic bones cause the femora to converge more than in males. In the condition genu valgum, ''genu valgum'' (knock knee), the femurs conve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
