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Shastasauridae
Shastasauridae is an extinct family of Triassic ichthyosaurs that includes the genera '' Shastasaurus'', ''Shonisaurus'' and ''Himalayasaurus''. Many other Triassic ichthyosaurs have been assigned to Shastasauridae in the past, but recent phylogenetic analyses suggest that these species form an evolutionary grade of early ichthyosaurs rather than a true clade or evolutionary grouping that can be called Shastasauridae. Shastasauridae was named by American paleontologist John Campbell Merriam in 1895 along with the newly described genus ''Shastasaurus''. In 1999, Ryosuke Motani erected the clade Shastasauria to include ''Shastasaurus'', ''Shonisaurus'', and several other traditional shastasaurids, defining it as a stem-based taxon including "all merriamosaurians more closely related to '' Shastasaurus pacificus'' than to ''Ichthyosaurus communis''." He also redefined Shastasauridae as a node-based taxon including "the last common ancestor of ''Shastasaurus pacificus'' and '' Besan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Himalayasaurus
''Himalayasaurus'' is an extinct genus of ichthyosaur from the Late Triassic Qulonggongba Formation of Tibet. The type species ''Himalayasaurus tibetensis'' was described in 1972 on the basis of fragmentary remains, including teeth, limb bones, and vertebrae.Z.-M. Dong. (1972). An ichthyosaur fossil from the Qomolangma Feng (Mt. Everest) region. ''Gu ji zhui dong wu yu gu ren lei yan jiu suo ji kan'' 9:7-10 The entire body length of ''Himalayasaurus'' is estimated to have been over in length. ''Himalayasaurus'' has since been considered a ''nomen dubium'' or "dubious name" because of the lack of features that set it apart from other ichthyosaurs, although the presence of distinct cutting edges on its teeth have more recently been proposed as a unique feature of the genus (cutting edges have also been found in the recently described ichthyosaur ''Thalattoarchon'' from the western United States). ''Himalayasaurus'' belongs to the family Shastasauridae, which includes other large-bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shonisaurus
''Shonisaurus'' is a very large genus of ichthyosaur. At least 37 incomplete fossil specimens of the marine reptile have been found in the Luning Formation of Nevada, USA. This formation dates to the late Carnian age of the late Triassic period, about 237–227 million years ago. Description left, Size of ''S. popularis'' (green) and '' Shastasaurus sikanniensis'' (red) compared with a human (blue) ''Shonisaurus'' lived during the Carnian stage of the late Triassic period. ''S. popularis'' measured around in length and in body mass. A second species from British Columbia was named ''Shonisaurus sikanniensis'' in 2004. ''S. sikanniensis'' was one of the largest marine reptiles of all time, measuring and weighing . However, phylogenetic studies later showed ''S. sikanniensis'' to be a species of '' Shastasaurus'' rather than ''Shonisaurus''. A new study published in 2013 reasserted the original classification, finding it more closely related to ''Shonisaurus'' than to ''Shasta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shastasaurus
''Shastasaurus'' ("Mount Shasta lizard") is a very large extinct genus of ichthyosaur from the middle and late Triassic, and is the largest known marine reptile.Hilton, Richard P., ''Dinosaurs and Other Mesozoic Animals of California'', University of California Press, Berkeley 2003 , at pages 90-91. Specimens have been found in the United States, Canada, and China. Description left, Size of '' Shonisaurus popularis'' (green) and ''S. sikanniensis'' (red), a possible species of ''Shastasaurus'', compared with a human ''Shastasaurus'' lived during the late Triassic period. The type species ''Shastasaurus pacificus'' is known from California. ''S. pacificus'' was a medium-sized ichthyosaur, measuring over in length and weighing . A second possible species of ''Shastasaurus'', ''S. sikanniensis'', is known from the Pardonet Formation British Columbia, dating to the middle Norian age (about 210 million years ago). If ''S.sikanniensis'' belongs to ''Shastasaurus'', it would be the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shastasaurus Sikanniensis
''Shastasaurus'' ("Mount Shasta lizard") is a very large extinct genus of ichthyosaur from the middle and late Triassic, and is the largest known marine reptile.Hilton, Richard P., ''Dinosaurs and Other Mesozoic Animals of California'', University of California Press, Berkeley 2003 , at pages 90-91. Specimens have been found in the United States, Canada, and China. Description left, Size of '' Shonisaurus popularis'' (green) and ''S. sikanniensis'' (red), a possible species of ''Shastasaurus'', compared with a human ''Shastasaurus'' lived during the late Triassic period. The type species ''Shastasaurus pacificus'' is known from California. ''S. pacificus'' was a medium-sized ichthyosaur, measuring over in length and weighing . A second possible species of ''Shastasaurus'', ''S. sikanniensis'', is known from the Pardonet Formation British Columbia, dating to the middle Norian age (about 210 million years ago). If ''S.sikanniensis'' belongs to ''Shastasaurus'', it would be the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaur
Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria). Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago ( Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurs were particularly abundant in the Late Triassic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shastasaurus Pacificus
''Shastasaurus'' ("Mount Shasta lizard") is a very large extinct genus of ichthyosaur from the middle and late Triassic, and is the largest known marine reptile.Hilton, Richard P., ''Dinosaurs and Other Mesozoic Animals of California'', University of California Press, Berkeley 2003 , at pages 90-91. Specimens have been found in the United States, Canada, and China. Description left, Size of '' Shonisaurus popularis'' (green) and ''S. sikanniensis'' (red), a possible species of ''Shastasaurus'', compared with a human ''Shastasaurus'' lived during the late Triassic period. The type species ''Shastasaurus pacificus'' is known from California. ''S. pacificus'' was a medium-sized ichthyosaur, measuring over in length and weighing . A second possible species of ''Shastasaurus'', ''S. sikanniensis'', is known from the Pardonet Formation British Columbia, dating to the middle Norian age (about 210 million years ago). If ''S.sikanniensis'' belongs to ''Shastasaurus'', it would be the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merriamosauria
Merriamosauria is an extinct clade of ichthyosaurs. It was named by Ryosuke Motani in his 1999 analysis of the relationships of ichthyopterygian marine reptiles and was defined in phylogenetic terms as a stem-based taxon including "the last common ancestor of ''Shastasaurus pacificus'' and '' Ichthyosaurus communis'', and all of its descendants." The name honours John Campbell Merriam. Based on this definition, Merriamosauria includes most ichthyosaurs except for several Triassic groups such as the clade Mixosauria, the family Cymbospondylidae, and perhaps the family Toretocnemidae. Merriamosaurs are characterized by features in their pectoral girdles and limb bones, including an extensive connection between the scapula and the coracoid bone, the absence of the first metacarpal and the absence of a pisiform bone. In addition to ''Shastasaurus,'' this clade includes ''Shonisaurus, Guizhouichthyosaurus,'' an unnamed Norian The Norian is a division of the Triassic Period. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaurs
Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria). Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago ( Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurs were particularly abundant in the Late Triass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brooks Range
The Brooks Range ( Gwich'in: ''Gwazhał'') is a mountain range in far northern North America stretching some from west to east across northern Alaska into Canada's Yukon Territory. Reaching a peak elevation of on Mount Isto, the range is believed to be approximately 126 million years old. In the United States, these mountains are considered a subrange of the Rocky Mountains, whereas in Canada they are considered separate, as the northern border of the Rocky Mountains is considered to be the Liard River far to the south in the province of British Columbia. While the range is mostly uninhabited, the Dalton Highway and Trans-Alaska Pipeline System run through the Atigun Pass (1,415 m, 4,643 ft) on their way to the oil fields at Prudhoe Bay on Alaska's North Slope. The Alaska Native villages of Anaktuvuk and Arctic Village, as well as the very small communities of Coldfoot, Wiseman, Bettles, and Chandalar, are the range's only settlements. In the far west, near the Wul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guizhouichthyosaurus
''Guizhouichthyosaurus'' is an extinct genus of ichthyosaur which is known primarily from the Xiaowa Formation of the lower Carnian stage of the Late Triassic in southwest China. The type species of this genus is ''Guizhouichthyosaurus tangae'', of which multiple skeletons are known. It has been reassigned as a species of the genus ''Shastasaurus'' in the past, though it has since been considered distinct. The ichthyosaurs ''Cymbospondylus asiaticus'', named in 2002, and ''Panjiangsaurus epicharis'', named in 2003, are junior synonyms of ''G. tangae''. The genus is also known from the Ladinian-aged Middle Triassic Zhuganpo Formation; additionally, the species ''"Callawayia" wollongangense'' may belong to ''Guizhouichthyosaurus''. ''Guizhouichthyosaurus'' is a large ichthyosaur, typically measuring approximately long with some specimens exceeding . The snout is long and powerful, and there is a low sagittal crest on the rear part of its skull. The tail is bent downwards near its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic Ichthyosaurs
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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