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Secodontosaurus Obtus1DB
''Secodontosaurus'' (meaning "cutting-tooth lizard") is an extinct genus of "pelycosaur" synapsids that lived from between about 285 to 272 million years ago during the Early Permian. Like the well known ''Dimetrodon'', ''Secodontosaurus'' is a carnivorous member of the Eupelycosauria family Sphenacodontidae and has a similar tall dorsal sail. However, its skull is long, low, and narrow, with slender jaws that have teeth that are very similar in size and shape—unlike the shorter, deep skull of ''Dimetrodon'' ("two-measure tooth"), which has large, prominent canine-like teeth in front and smaller slicing teeth further back in its jaws. Its unusual long, narrow jaws suggest that ''Secodontosaurus'' may have been specialized for catching fish or for hunting prey that lived or hid in burrows or crevices. Although no complete skeletons are currently known, ''Secodontosaurus'' likely ranged from about in length, weighing up to . Fossils of ''Secodontosaurus'' have been found in Texa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisuralian
The Cisuralian is the first Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian (geology), Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Mya. The Cisuralian is often synonymous with the informal terms early Permian or lower Permian. It corresponds approximately with the Wolfcampian in southwestern North America. The series saw the appearance of beetles and Fly, flies and was a relatively stable warming period of about 21 million years. Name and background The Cisuralian is the first series or epoch of the Permian. The Cisuralian was preceded by the last Pennsylvanian epoch (Gzhelian) and is followed by the Permian Guadalupian Epoch. The name "Cisuralian" was proposed in 1982, and approved by the International Subcommission on Permian Stratigraphy in 1996. The Ci ... [...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] |
Ctenospondylus
''Ctenospondylus'' ("comb vertebra") is an extinct genus of sphenacodontid synapsid Species were about three meters (ten feet) long. The genus is known only from the 'Seymouran' Land Vertebrate Faunachron, which is equivalent to the upper part of the Artinskian stage and the lowermost Kungurian stage of the Early Permian. Its fossils were found in the U.S. states of Ohio and Texas. It was a carnivore and preyed upon animals close to its size. ''Ctenospondylus'' had a long tail, short back spines, and a very deep yet narrow skull with massive jaws that had sharp teeth. Because of its large size, it was probably the apex predator in its environment, and might have competed with other predators like ''Dimetrodon'' for food. A sphenacodontid, it was a close relative of ''Dimetrodon''. In 1936, Alfred Sherwood Romer named the type species ''Ctenospondylus casei''. The generic name, from Greek κτείς, ''kteis'', "comb", and σφόνδυλος, ''sphondylos'', "vertebra", refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodon
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related '' Dimetrodon'', ''Sphenacodon'' was a carnivorous member of the Eupelycosauria family Sphenacodontidae. However, ''Sphenacodon'' had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in ''Dimetrodon''. Fossils of ''Sphenacodon'' are known from New Mexico and the Utah–Arizona border region in North America. Researchers currently recognize two species: ''Sphenacodon ferox'' (the type species) and ''Sphenacodon ferocior''. ''Sphenacodon ferocior'' can be up to 40% larger in overall size (at about long) compared to ''Sphenacodon ferox'' (at about ). In addition, the dorsal spines in ''Sphenacodon ferocior'' are proportionately 45% taller than in ''Sphenacodon ferox''. The recent discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Wendell Williston
Samuel Wendell Williston (July 10, 1852 – August 30, 1918) was an American educator, entomologist, and paleontologist who was the first to propose that birds developed flight cursorially (by running), rather than arboreally (by leaping from tree to tree). He was a specialist on the flies, Diptera. He is remembered for Williston's law, which states that parts in an organism, such as arthropod limbs, become reduced in number and specialized in function through evolutionary history. Early life Williston was born in Boston, Massachusetts to Samuel Williston and Jane A. Williston née Turner. As a young child, Williston's family travelled to Kansas Territory in 1857 under the auspices of the New England Emigrant Aid Company to help fight the extension of slavery. He was raised in Manhattan, Kansas, attended public high school there, and graduated from Kansas State Agricultural College (now Kansas State University) in 1872, afterwards receiving a Master of Arts from that instituti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ermine Cowles Case
Ermine Cowles Case (1871–1953), invariably known as E.C. Case, was a prominent American paleontologist in the second generation that succeeded Othniel Charles Marsh and Edward Drinker Cope. A graduate of the University of Kansas, with a PhD from the University of Chicago (1896), Case became a paleontologist of international stature while working at the University of Michigan. He was a Member of the American Philosophical Society (1931). Case began by sorting out some of the taxonomic synonymies and other puzzles created by the "Bone Wars" of the two giants of the heroic age of dinosaur-hunting in the American West, in a series of three monographs dealing with the vertebrates of the Permian or Permo-Carboniferous of North America. Case then turned to his lifelong interest in filling in the fossil record of Permian and Carboniferous vertebrates from the ' Red Beds' of Texas, New Mexico, and Oklahoma. He also made extensive Jurassic collections at Como Bluff, Wyoming, in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacob Boll
Jacob Boll (28 May 1828 – 29 September 1880) was a Swiss naturalist and entomologist especially noted for his exploration of the Texas Red Beds. Boll was born 1828 in Würenlos, Switzerland, and educated as a pharmacist in Switzerland and Germany. Established as a naturalist, he turned his attention to microlepidoptera and established contact with Philipp Christoph Zeller. In 1856, his parents and siblings travelled to Texas and joined the La Réunion socialist utopian community. The Bolls left the commune after the first year and established a farm in Dallas near the current Baylor Medical Center. Jacob visited his family in Texas circa 1867, and then returned to Switzerland. In 1869 he met with Louis Agassiz at Harvard, proceeding to Texas to collect animals for the Harvard Museum of Comparative Zoology. Returning to Switzerland he became a professional collector, working for Eduard Dämle and the Swiss government. Similar arrangements were made with Agassiz and in 1870 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiacodon
''Ophiacodon'' (meaning "snake tooth") is an extinct genus of synapsid belonging to the family Ophiacodontidae that lived from the Late Carboniferous to the Early Permian in North America and Europe. The genus was named along with its type species ''O. mirus'' by paleontologist Othniel Charles Marsh in 1878 and currently includes five other species. As an ophiacodontid, ''Ophiacodon'' is one of the most basal synapsids and is close to the evolutionary line leading to mammals. Description ''Ophiacodon'' has a large skull with a deep snout. It has the longest skull of any early synapsid, reaching up to in one specimen. The jaws are lined with many small teeth. It was larger than most other tetrapods (four-limbed vertebrates) of its time, ranging from in length and in weight. Specimens of ''Ophiacodon'' vary greatly in size. These differences in size were once used to distinguish species, but are now recognized as ontogenetic variations related to the ages of individuals. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Drinker Cope
Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of 19. Though his father tried to raise Cope as a gentleman farmer, he eventually acquiesced to his son's scientific aspirations. Cope married his cousin and had one child; the family moved from Philadelphia to Haddonfield, New Jersey, although Cope would maintain a residence and museum in Philadelphia in his later years. Cope had little formal scientific training, and he eschewed a teaching position for field work. He made regular trips to the American West, prospecting in the 1870s and 1880s, often as a member of United States Geological Survey teams. A personal feud between Cope and paleontologist Othniel Charles Marsh led to a period of intense fossil-finding competition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert R
Robert Lee Rayford (February 3, 1953 – May 15 1969), sometimes identified as Robert R. due to his age, was an American teenager from Missouri who has been suggested to represent the earliest confirmed case of HIV/AIDS in North America based on evidence which was published in 1988 in which the authors claimed that medical evidence indicated that he was "infected with a virus closely related or identical to human immunodeficiency virus type 1." Rayford died of pneumonia, but his other symptoms baffled the doctors who treated him. A study published in 1988 reported the detection of antibodies against HIV. Results of testing for HIV genetic material were reported once at a scientific conference in Australia in 1999; however, the data has never been published in a peer-reviewed medical or scientific journal. Background Robert Rayford was born on February 3, 1953, in St. Louis, Missouri to Constance Rayford (September 12, 1931 – April 3, 2011) and Joseph Benny Bell (March 24, 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secodontosaurus Obtus1DB
''Secodontosaurus'' (meaning "cutting-tooth lizard") is an extinct genus of "pelycosaur" synapsids that lived from between about 285 to 272 million years ago during the Early Permian. Like the well known ''Dimetrodon'', ''Secodontosaurus'' is a carnivorous member of the Eupelycosauria family Sphenacodontidae and has a similar tall dorsal sail. However, its skull is long, low, and narrow, with slender jaws that have teeth that are very similar in size and shape—unlike the shorter, deep skull of ''Dimetrodon'' ("two-measure tooth"), which has large, prominent canine-like teeth in front and smaller slicing teeth further back in its jaws. Its unusual long, narrow jaws suggest that ''Secodontosaurus'' may have been specialized for catching fish or for hunting prey that lived or hid in burrows or crevices. Although no complete skeletons are currently known, ''Secodontosaurus'' likely ranged from about in length, weighing up to . Fossils of ''Secodontosaurus'' have been found in Texa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Bakker
Robert Thomas Bakker (born March 24, 1945) is an American paleontologist who helped reshape modern theories about dinosaurs, particularly by adding support to the theory that some dinosaurs were endothermic (warm-blooded). Along with his mentor John Ostrom, Bakker was responsible for initiating the ongoing " dinosaur renaissance" in paleontological studies, beginning with Bakker's article "Dinosaur Renaissance" in the April 1975 issue of ''Scientific American''. His specialty is the ecological context and behavior of dinosaurs. Bakker has been a major proponent of the theory that dinosaurs were warm-blooded, smart, fast, and adaptable. He published his first paper on dinosaur endothermy in 1968. His seminal work, '' The Dinosaur Heresies,'' was published in 1986. He revealed the first evidence of parental care at nesting sites for ''Allosaurus''. He also observed evidence in support of Eldredge and Gould's theory of punctuated equilibrium in dinosaur populations. Bakker curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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