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Tiktaalik
''Tiktaalik'' (; Inuktitut ) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the Late Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals). It may have grown up to in length. Unearthed in Arctic Canada, ''Tiktaalik'' is a non-tetrapod member of Osteichthyes (bony fish), complete with scales and gills – but it has a triangular, flattened head and unusual, cleaver-shaped fins. Its fins have thin ray bones for paddling like most fish, but they also have sturdy interior bones that would have allowed Tiktaalik to prop itself up in shallow water and use its limbs for support as most four-legged animals do. Those fins and other mixed characteristics mark ''Tiktaalik'' as a crucial transition fossil, a link in evolution from swimming fish to four-legged vertebrates. This and similar animals might be the common ancestors of all vertebrate terrestrial fauna: amphibians, reptiles, birds, and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiktaalik Skull Front
''Tiktaalik'' (; Inuktitut ) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the Late Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals). It may have grown up to in length. Unearthed in Arctic Canada, ''Tiktaalik'' is a non-tetrapod member of Osteichthyes (bony fish), complete with scales and gills – but it has a triangular, flattened head and unusual, cleaver-shaped fins. Its fins have thin ray bones for paddling like most fish, but they also have sturdy interior bones that would have allowed Tiktaalik to prop itself up in shallow water and use its limbs for support as most four-legged animals do. Those fins and other mixed characteristics mark ''Tiktaalik'' as a crucial transition fossil, a link in evolution from swimming fish to four-legged vertebrates. This and similar animals might be the common ancestors of all vertebrate terrestrial fauna: amphibians, reptiles, birds, and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapod
Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct therapsids and all extant mammals). Tetrapods evolved from a clade of primitive semiaquatic animals known as the Tetrapodomorpha which, in turn, evolved from ancient lobe-finned fish (sarcopterygians) around 390 million years ago in the Middle Devonian period; their forms were transitional between lobe-finned fishes and true four-limbed tetrapods. Limbed vertebrates (tetrapods in the broad sense of the word) are first known from Middle Devonian trackways, and body fossils became common near the end of the Late Devonian but these were all aquatic. The first crown-tetrapods (last common ancestors of extant tetrapods capable of terrestrial locomotion) appeared by the very early Carboniferous, 350 million years ago. The specific aquatic ancestors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transitional Fossil
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors. In 1859, when Charles Darwin's ''On the Origin of Species'' was first published, the fossil record was poorly known. Darwin described the perceived lack of transitional fossils as "the most obvious and gravest objection which can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neil Shubin
Neil Shubin (born December 22, 1960) is an American paleontologist, evolutionary biologist and popular science writer. He is the Robert R. Bensley Professor of Organismal Biology and Anatomy, Associate Dean of Organismal Biology and Anatomy and Professor on the Committee of Evolutionary Biology at the University of Chicago along with being the Provost of the Field Museum of Natural History. He is best known for his co-discovery of ''Tiktaalik roseae'' with Ted Daeschler and Farish Jenkins. Biography Raised in Overbrook Hills section of Lower Merion Township (contiguous to City of Philadelphia) and a graduate of Lower Merion High School, Shubin earned a A.B. from Columbia College of Columbia University in 1982 and a Ph.D. in organismic and evolutionary biology from Harvard University in 1987. He also studied at the University of California, Berkeley. Shubin was elected to the National Academy of Sciences in 2011. Shubin was ABC News' "Person of the Week" in April 2006 when ''Ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcopterygian
Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass including amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (with mammals being the only extant group), evolved from certain sarcopterygians; under a cladistic view, tetrapods are themselves considered a subgroup within Sarcopterygii. The known extant non-tetrapod sarcopterygians include two species of coelacanths and six species of lungfishes. Characteristics Early lobe-finned fishes are bony fish with fleshy, lobed, paired fins, which are joined to the body by a single bone. The fins of lobe-finned fishes differ from those of all other fish in that each is borne on a fleshy, lobelike, scaly stalk extending from the body. The scales of sarcopterygians are true scaloids, consisting of lamellar bone surro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farish Jenkins
Farish Alston Jenkins (May 19, 1940 – November 11, 2012) was a professor at Harvard University who studied and taught paleontology. His discoveries included a transitional creature with characteristics of both fish and land animals — ''Tiktaalik roseae'' —and one of the earliest known frogs, '' Prosalirus bitis''. Early life Farish Jenkins was born in Manhattan on May 19, 1940. He was the oldest of three sons of a marketing executive but was raised by his grandmother in Colorado while his father served in World War II. While he was a student at Princeton, studying geology, Jenkins met Eleanor Tracy. He later married her and they had two children — Henry Edgar and Katherine Temperance. He obtained a master's and doctorate from Yale and served as a captain in the United States Marine Corps. As a graduate student at Yale, Jenkins took a trip to Nairobi where he is said to have taken his first interest in live animal research: "At the time, black rhinos in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ted Daeschler
Edward B. 'Ted' Daeschler is an American vertebrate paleontologist and Associate Curator and Chair of Vertebrate Biology at the Academy of Natural Sciences in Philadelphia. He is a specialist in fish paleontology, especially in the Late Devonian, and in the development of the first limbed vertebrates. He is the discoverer of the transitional fossil tetrapod '' Hynerpeton bassetti'', and a Devonian fish-like specimen of ''Sauripterus taylori'' with fingerlike appendages, and was also part of a team of researchers that discovered the transitional fossil ''Tiktaalik''. He received a Ph.D. from the University of Pennsylvania in 1998. He has held recent research grants from the National Science Foundation, the National Geographic Society, and other donors. He is also known for his work on the preservation of natural history collections."Endangered collections" by Rex Dalton Nature 446, 605-606 (5 April 2007) Selected publications *Daeschler, E. B. and N. H. Shubin. 1998. Fish with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2006 In Paleontology
Plants Ferns and fern allies Angiosperms Arthropods Insects Tetrapodomorphs Amphibians Newly named temnospondylians Newly named amphibians Ichthyosaurs Lepidosauromorphs Newly named basal lepidosauromorphs Newly named plesiosaurs Newly named squamates Turtles Archosauromorphs Newly named crurotarsans Newly named dinosaurs * Vickaryous, M K., 2006, New information on the cranial anatomy of Edmontonia rugosidens Gilmore, a Late Cretaceous nodosaurid dinosaur from Dinosaur Provincial Park, Alberta: JVP, v. 26, n. 4: 1011–1013. Data are courtesy of George Olshevky's dinosaur genera list. Newly named birds Newly named pterosaurs Synapsids Non-mammalian Mammals Trace fossils * The trace fossil genera ''Nihilichnus'' (''Nihilichnus nihilicus'' and ''Nihilichnus mortalis''), ''Machichnus'' (''Machichnus regularis,'' ''Machichnus multilineatus'', and ''Machichnus bohemicus'') and ''Brutalichnus'' (''Brutalichnus'' ''brutalis'') are described fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellesmere Island
Ellesmere Island ( iu, script=Latn, Umingmak Nuna, lit=land of muskoxen; french: île d'Ellesmere) is Canada's northernmost and List of Canadian islands by area, third largest island, and the List of islands by area, tenth largest in the world. It comprises an area of , slightly smaller than Great Britain, and the total length of the island is . Lying within the Arctic Archipelago, Ellesmere Island is considered part of the Queen Elizabeth Islands. Cape Columbia at 83°06′ is the northernmost point of land in Canada and one of the northernmost points of land on the planet (the northernmost point of land on Earth is the nearby Kaffeklubben Island of Greenland). The Arctic Cordillera mountain system covers much of Ellesmere Island, making it the most mountainous in the Arctic Archipelago. More than one-fifth of the island is protected as Quttinirpaaq National Park. In 2021, the population of Ellesmere Island was recorded at 144. There are three settlements: Alert, Nunavut, Aler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Museum
The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is popular for the size and quality of its educational and scientific programs, and its extensive scientific-specimen and artifact collections. The permanent exhibitions, which attract up to two million visitors annually, include fossils, current cultures from around the world, and interactive programming demonstrating today's urgent conservation needs. The museum is named in honor of its first major benefactor, Marshall Field, the department-store magnate. The museum and its collections originated from the 1893 World's Columbian Exposition and the artifacts displayed at the fair. The museum maintains a temporary exhibition program of traveling shows as well as in-house produced topical exhibitions. The professional staff maintains collections of over 24 million specimens and objects tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academy Of Natural Sciences
The Academy of Natural Sciences of Drexel University, formerly the Academy of Natural Sciences of Philadelphia, is the oldest natural science research institution and museum in the Americas. It was founded in 1812, by many of the leading naturalists of the young American republic with an expressed mission of "the encouragement and cultivation of the sciences". It has sponsored expeditions, conducted original environmental and systematics research, and amassed natural history collections containing more than 17 million specimens. The Academy also organizes public exhibits and educational programs for both schools and the general public. History During the first decades of the United States, Philadelphia was the cultural capital and one of the country's commercial centers. Two of the city's institutions, the Library Company and the American Philosophical Society, were centers of enlightened thought and scientific inquiry. The increasing sophistication of the earth and life scie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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