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Secodontosaurus
''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] |
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] |
Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontidae. The most prominent feature of ''Dimetrodon'' is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It walked on four legs and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have been found in Germany. Over a dozen species have been named since the genus was first erected in 1878. ''Dimetrodon'' is often mistaken for a dinosaur or as a contemporary of dinosaurs in popular culture, but it became extinct some 40 million years before the first appearance of dinosaurs. Reptile-li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodontidae
Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family of small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian pelycosaurs. The most recent one, ''Dimetrodon angelensis'', is from the late Kungurian or early Roadian San Angelo Formation. However, given the notorious incompleteness of the fossil record, a recent study concluded that the Sphenacodontidae may have become extinct as recently as the early Capitanian. Primitive forms were generally small (60 cm to 1 meter), but during the later part of the early Permian these animals grew progressively larger (up to 3 meters or more), to become the top predators of their environments. Sphenacodontid fossils are so far known only from North America and Europe. Characteristics The skull is long, deep and narrow, an adaptation for strong jaw muscles. The front teeth are large and dagger-like, whereas the teeth in the sides and rear of the jaw are much smaller (hence the name of the well-kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptovenator
''Cryptovenator'' (''Crypto'', from Greek kryptos (hidden, secret); ''venator'', from Latin (hunter)) is an extinct genus of sphenacodontid pelycosaurs which existed in Germany during the latest Carboniferous (late Gzhelian age, 300 Ma ± 2.4 Ma). It is known from the holotype LFN−PW 2008/5599−LS, an anterior right mandible fragment, recovered from a dark, fine grained sandstone of the middle Remigiusberg Formation. It was first named by Jörg Fröbisch, Rainer R. Schoch, Johannes Müller, Thomas Schindler and Dieter Schweiss in 2011 and the type species is ''Cryptovenator hirschbergeri''. Phylogeny Cladogram after Fröbisch ''et al.'', 2011: See also * List of pelycosaurs This list of pelycosaurs is an attempt to create a comprehensive listing of all genera that have ever been included in the synapsida excluding therapsida and purely vernacular terms. The list includes all commonly accepted genera, but also genera t ... References Sphenacodontidae Carboni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapsid
Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptiles and birds. The group includes mammals and every animal more closely related to mammals than to sauropsids. Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye orbit, leaving a bony arch beneath each; this accounts for their name. The distinctive temporal fenestra developed about 318 million years ago during the Late Carboniferous period, when synapsids and sauropsids diverged, but was subsequently merged with the orbit in early mammals. Traditionally, non-mammalian synapsids were believed to have evolved from reptiles, and therefore described as mammal-like reptiles in classical systematics, and primitive synapsids were also referred to as pelycosaurs, or pelycosaur-gr ... [...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] |
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic period (), and the Classical period (). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical periods of the language. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regarded as a separate historical stage, although its earliest form closely resembles Attic Greek and its latest form approaches Medieval Greek. There were several regional dialects of Ancient Greek, of which Attic Greek developed into Koine. Dia ... [...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] |
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] |
Houston Museum Of Natural Science
The Houston Museum of Natural Science (abbreviated as HMNS) is a natural history museum located on the northern border of Hermann Park in Houston, Texas, United States. The museum was established in 1909 by the Houston Museum and Scientific Society, an organization whose goals were to provide a free institution for the people of Houston focusing on education and science. Museum attendance totals over two million visitors each year. The museum complex consists of a central facility with four floors of natural science halls and exhibits, the Burke Baker Planetarium, the Cockrell Butterfly Center, and the Wortham Giant Screen Theatre (formerly known as the Wortham IMAX Theatre). The museum is one of the most popular in the United States and ranks just below New York City's American Museum of Natural History and Metropolitan Museum of Art and the M. H. de Young Memorial Museum in San Francisco in most attendance amongst non- Smithsonian museums. Much of the museum's popularity is attr ... [...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] |
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] |
