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Leptaucheniini
''Leptauchenia'' is an extinct goat-like genus of terrestrial herbivore belonging to the oreodont family Merycoidodontidae, and the type genus of the tribe Leptaucheniini. The genus was endemic to North America during the Late Oligocene to Early Miocene (33.9—16.3 mya) and lived for approximately . Morphology Because the eyes and nostrils were placed high on the head, it was long assumed that ''Leptauchenia'' was an aquatic, or semi-aquatic animal. However, because their fossils have never been found in floodplain deposits or river channels, and their abundance in fossil sand dunes, Donald Prothero suggests that they were desert-dwelling animals.Prothero, D. R., and F. Sanchez. 2005. Review of the leptauchenine oreodonts (Mammalia: Artiodacttyla). ''New Mexico Museum of Natural History and Science Bulletin.'' According to Prothero's interpretation, the high-placed eyes and nostrils served to filter out sand while burrowing, or while digging themselves free of sand dunes. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oreodont
Merycoidodontoidea, sometimes called "oreodonts" or "ruminating hogs", is an extinct superfamily of prehistoric cud-chewing artiodactyls with short faces and fang-like canine teeth. As their name implies, some of the better known forms were generally hog-like, and the group has traditionally been placed within the Suina (pigs, peccaries and their ancestors), though some recent work suggests they may have been more closely related to camels.Spaulding, M., O'Leary, M.A. & Gatesy, J. (2009): Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution. '' PLoS ONE'' no 4(9): e7062.article/ref> "Oreodont" means "mountain teeth", referring to the appearance of the molars. Most oreodonts were sheep-sized, though some genera grew to the size of cattle. They were heavy-bodied, with short four-toed hooves and comparatively long tails. The animals would have looked rather pig- or sheep-like, but features ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptauchenia Decora
''Leptauchenia'' is an extinct goat-like genus of terrestrial herbivore belonging to the oreodont family Merycoidodontidae, and the type genus of the tribe Leptaucheniini. The genus was endemic to North America during the Late Oligocene to Early Miocene (33.9—16.3 mya) and lived for approximately . Morphology Because the eyes and nostrils were placed high on the head, it was long assumed that ''Leptauchenia'' was an aquatic, or semi-aquatic animal. However, because their fossils have never been found in floodplain deposits or river channels, and their abundance in fossil sand dunes, Donald Prothero suggests that they were desert-dwelling animals.Prothero, D. R., and F. Sanchez. 2005. Review of the leptauchenine oreodonts (Mammalia: Artiodacttyla). ''New Mexico Museum of Natural History and Science Bulletin.'' According to Prothero's interpretation, the high-placed eyes and nostrils served to filter out sand while burrowing, or while digging themselves free of sand dunes. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merycoidodontidae
Merycoidodontoidea, sometimes called "oreodonts" or "ruminating hogs", is an extinct superfamily of prehistoric cud-chewing artiodactyls with short faces and fang-like canine teeth. As their name implies, some of the better known forms were generally hog-like, and the group has traditionally been placed within the Suina (pigs, peccaries and their ancestors), though some recent work suggests they may have been more closely related to camels.Spaulding, M., O'Leary, M.A. & Gatesy, J. (2009): Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution. '' PLoS ONE'' no 4(9): e7062.article/ref> "Oreodont" means "mountain teeth", referring to the appearance of the molars. Most oreodonts were sheep-sized, though some genera grew to the size of cattle. They were heavy-bodied, with short four-toed hooves and comparatively long tails. The animals would have looked rather pig- or sheep-like, but features ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and 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 the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of 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 changes during the Oligocene included a global expansion o ... [...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 made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 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 Amphicyonidae is an extinct family of terrestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White River Fauna
The White River Fauna are fossil animals found in the White River Badlands of South Dakota, Wyoming, Colorado and Nebraska in the United States including Badlands National Park. The fossils have been found in the White River Formation, Chadron Formation, Brule Formation, and the Arikaree Formation. Animals from the White River Badlands date from the Eocene, Oligocene, the Miocene, and the Pliocene Epochs. List Genera include: See also * :White River Fauna Further reading * Rachel Benton, ''The White River Badlands: Geology and Paleontology'', Indiana University Press 2015 * William Berryman Scott William Berryman Scott (February 12, 1858 – March 29, 1947) was an American vertebrate paleontologist, authority on mammals, and principal author of the White River Oligocene monographs. He was a professor of geology and paleontology at P ..., ''A history of land mammals in the western hemisphere'', MacMillan Publishing Company, 1913 References Paleogene animals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene Genus Extinctions
The Oligocene ( ) is a geologic epoch of the Paleogene Period and 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 the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of 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 changes during the Oligocene included a global expansion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene Even-toed Ungulates
The Oligocene ( ) is a geologic epoch of the Paleogene Period and 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 the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of 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 changes during the Oligocene included a global expansion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sespia
''Sespia'' ("of Sespe Creek") is an extinct genus of oreodont endemic to North America. They lived during the Late Oligocene 26.3—24.8 mya, existing for approximately . ''Sespia'' was cat to goat-sized and desert-dwelling. The genus was closely related to the larger ''Leptauchenia''. Fossils of the best known species, the cat-sized ''S. californica'', have been found California and are known from literally thousands of specimens. The largest species, the goat-sized ''S. ultima'', is known from late Oligocene deposits in Nebraska. ''S. ultima'' was once placed in a separate, monotypic, genus as ''Megasespia middleswarti''. Other species were once placed within ''Leptauchenia''. References External linksSan Diego Natural History Museum The San Diego Natural History Museum is a museum located in Balboa Park in San Diego, California. It was founded in 1874 as the San Diego Society of Natural History. It is the second oldest scientific institution west of the Mississ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donald Prothero
Donald Ross Prothero (February 21, 1954) is an American geologist, paleontologist, and author who specializes in mammalian paleontology and magnetostratigraphy, a technique to date rock layers of the Cenozoic era and its use to date the climate changes which occurred 30–40 million years ago. He is the author or editor of more than 30 books and over 300 scientific papers, including at least 5 geology textbooks. Stephen Jay Gould cited Prothero's research on the lack of response to climate change in mammals from the Eocene, Oligocene and Pleistocene epochs to support the punctuated equilibrium model of evolution. He called Prothero "the best punctuated equilibrium researcher on the West Coast". Biography Prothero grew up in the Glendale, California area, the son of Clifford R. Prothero (1920–2004), a technical illustrator for Lockheed, and Shirley M. (McDonald) Prothero (1924–2016), an artist and homemaker. He attended the University of California, Riverside where he studie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annum
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
