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Leptaucheniinae
Leptaucheniinae ("Delicate Necks") was a taxon of small, goat-like oreodonts with proportionally big heads found throughout North America during the Late Oligocene. Because skeletons of '' Leptauchenia'' and ''Sespia'' have been found by the literal thousands, they are often quoted as being the most numerous fossil mammals in North America during the Late Oligocene. They had high-crowned, hypsodont teeth which were used to chew gritty vegetation. Because the eyes and nostrils were placed high on the head, it was long assumed that ''Leptauchenia'' and ''Sespia'' were aquatic, or semi-aquatic animals. However, because their fossils have never been found in floodplain deposits or river channels, and their plague-like abundance in fossil sand dunes, 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 ... [...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] |
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] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptauchenia
''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] |
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] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San 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 Mississippi and the oldest in Southern California. The present location of the museum was dedicated on January 14, 1933. A major addition to the museum was dedicated in April 2001, doubling exhibit space. History The San Diego Natural History Museum grew out of the San Diego Society of Natural History, which was founded on October 9, 1874. The Natural History Society was founded by George W. Barnes, Daniel Cleveland, Charles Coleman, E. W. Hendrick and O. N. Sanford. It is the oldest scientific institution in southern California, and the second oldest west of the Mississippi. In its initial years, the San Diego Society of Natural History was the region's primary source of scientific culture, serving a small but growing community eager for information a ... [...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] |
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] |
Chattian Extinctions
The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage of the Miocene). Stratigraphic definition The Chattian was introduced by Austrian palaeontologist Theodor Fuchs in 1894. Fuchs named the stage after the Chatti, a Germanic tribe.Berry, Edward W"The Mayence Basin, a Chapter of Geologic History" ''The Scientific Monthly'', Vol. 16, No. 2, February 1923. pp. 114. Retrieved March 18, 2020. The original type locality was near the German city of Kassel. The base of the Chattian is at the extinction of the foram genus ''Chiloguembelina'' (which is also the base of foram biozone P21b). An official GSSP for the Chattian Stage was ratified in October of 2016. The top of the Chattian Stage (which is the base of the Aquitanian Stage, Miocene Series and Neogene System) is at the first appearanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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