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''Corythosaurus'' is a genus of hadrosaurid "duck-billed" dinosaur from the Upper Cretaceous Period, about 77–75.7 million years ago. It lived in what is now North America. Its name means "helmet lizard", derived from Greek κόρυς. It was named and described in 1914 by Barnum Brown. ''Corythosaurus'' is now thought to be a lambeosaurine, related to ''Nipponosaurus'', ''Velafrons'', ''Hypacrosaurus'', and ''Olorotitan''. ''Corythosaurus'' has an estimated length of , and has a skull, including the crest, that is tall. ''Corythosaurus'' is known from many complete specimens, including the nearly complete holotype found by Brown in 1911. The holotype skeleton is only missing the last section of the tail, and part of the forelimbs, but was preserved with impressions of polygonal scales. ''Corythosaurus'' is known from many skulls with tall crests. The crests resemble the crests of the cassowary and a Corinthian helmet. The most likely function of the crest is thought to be vocalization. As in a trombone, sound waves would travel through many chambers in the crest, and then get amplified when ''Corythosaurus'' exhaled. A ''Corythosaurus'' specimen has been preserved with its last meal in its chest cavity. Inside the cavity were remains of conifer needles, seeds, twigs, and fruits: ''Corythosaurus'' probably fed on all of these. The two species of ''Corythosaurus'' are both present in slightly different levels of the Dinosaur Park Formation. Both still co-existed with theropods and other ornithischians, like ''Daspletosaurus'', ''Brachylophosaurus'', ''Parasaurolophus'', ''Scolosaurus'', and ''Chasmosaurus''. ==Discovery and species== The first specimen, AMNH 5240, was discovered in 1911 by Barnum Brown in Red Deer River, Alberta, Canada, and secured by him in the Fall of 1912.〔Lowell Dingus and Mark Norell, 2011, ''Barnum Brown: The Man Who Discovered'' Tyrannosaurus rex, University of California Press, p. 143〕〔 As well as an almost complete skeleton, the find was notable because impressions of much of the creature's skin had also survived.〔 The specimen came from the Belly River Group of the province.〔 The left or underside of the skeleton was preserved in carbonaceous clay, making it difficult to expose the skin.〔 The skeleton was articulated, and only missing about the last of the tail and the forelimbs.〔 Both scapulae and coracoids are preserved in position, but the rest of the forelimbs are gone, except for phalanges and pieces of humeri, ulnae and radii. Apparently the remaining forelimbs were weathered or eroded away.〔 Impressions of the integument were preserved covering over a large part of the skeletons outlining, and shows the form of the body.〔 Another specimen, AMNH 5338, was found in 1914 by Brown and Peter Kaisen. Both specimens are now housed in the American Museum of Natural History in their original death poses.〔 The type species ''Corythosaurus casuarius'' was named by Barnum Brown in 1914, based on the first specimen collected by him in 1912. AMNH 5240 is thus the holotype. In 1916, the original author, Brown, published a more detailed description which was also based on AMNH 5338, which specimen is therefore the plesiotype. ''Corythosaurus'' is among many lambeosaurines that possess crests, and it was the crest that lends ''Corythosaurus'' its name. The generic name ''Corythosaurus'' is derived from Greek κόρυθος, ''korythos'', "Corinthian helmet", and means "helmeted lizard".〔 The specific name ''casuarius'' refers to the cassowary, a bird with a similar skull crest. The full binomial of ''Corythosaurus casuarius'' thus means "Cassowary-like reptile, with a Corinthian helmet crest".〔(【引用サイトリンク】url=http://www.carnegiemnh.org/online/dinosaurs/corythosaurus.html )〕 The two best preserved specimens of ''Corythosaurus'' found, by Charles H. Sternberg in 1912, were lost on 6 December 1916 while being carried to the United Kingdom, during World War One. They were being sent to Arthur Smith Woodward, a paleontologist of the British Museum of Natural History in England, when the ship transporting them was sunk by the German merchant raider SMS Möwe in the middle of the ocean.〔p. 495 in Tanke, D.H. & Carpenter, K. (2001).〕 There were formerly up to seven species described, including ''C. casuarius'', ''C. bicristatus'' Parks 1935, ''C. brevicristatus'' Parks 1935, ''C. excavatus'' Gilmore 1923, ''C. frontalis'' Parks 1935, and ''C. intermedius'' Parks 1923. In 1975 Peter Dodson studied the differences between the skulls and crests of different species of lambeosaurine dinosaurs. He found that the differences in size and shape may have actually been related to the gender and age of the animal. Now only one species is recognized for certain, ''C. casuarius'',〔 although ''C. intermedius'' has been recognized as valid in some studies. It is based on specimen ROM 776, a skull found by Levi Sternberg in 1920 and was named by William Parks in 1923, who had originally named it ''Stephanosaurus intermedius'' earlier that year.〔W.A. Parks, 1923, "New species of crested trachodont dinosaur", ''Bulletin of the Geological Society of America'' 34: 130〕 The specific name of ''C. intermedius'' is derived from its apparent intermediate position according to Parks.〔Parks, W.A. (1923). "''Corythosaurus intermedius'', a new species of trachodont dinosaur". ''University of Toronto Studies, Geological Series'' 15: 5–57〕〔〔N. E. Campione; K. S. Brink; E. A. Freedman; C. T. McGarrity; D. C. Evans. (2013). "‘''Glishades ericksoni''’, an indeterminate juvenile hadrosaurid from the Two Medicine Formation of Montana: implications for hadrosauroid diversity in the latest Cretaceous (Campanian-Maastrichtian) of western North America". ''Palaeobiodiversity and Palaeoenvironments'' 93:65–75〕 ''C. intermedius'' lived at a slightly later time in the Campanian than ''C. casuarius'', and the two species are not identical, which supported the separation of them in a 2009 study.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Corythosaurus」の詳細全文を読む スポンサード リンク
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