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''Suchomimus'' ("crocodile mimic") is a genus of large spinosaurid dinosaur with a crocodile-like skull that lived between 121–113 million years ago, during the late Aptian stage of the Cretaceous period in Niger, Africa.〔 ].〕 The only species named in the genus is ''Suchomimus tenerensis''. ==Description== The length of the type specimen of ''Suchomimus'', a subadult, was initially estimated at . In 2007, its weight was estimated at between . In 2010, Gregory S. Paul gave lower estimations of 9.5 metres and 2.5 tonnes.〔Paul, G.S., 2010, ''The Princeton Field Guide to Dinosaurs'', Princeton University Press p. 87〕 The describers established some unique derived traits or autapomorphies of ''Suchomimus''. The praemaxilla has an upward branch excluding the maxilla from the bony nostril. The neural spines on the rear dorsal, sacral and front tail vertebrae are expanded in side view. The upper corners of the humerus are robust. The humerus has a boss above the condyle that contacts the radius, that is hook-shaped.〔 Unlike most giant theropods, ''Suchomimus'' had a very long, low snout and narrow jaws, formed by a forward expansion of the premaxilla and the anterior ramus of the maxilla. The jaws have about 122 conical teeth, pointed but not very sharp and curving slightly backward, with fine serrations. The tip of the snout was enlarged sideways and carried a "rosette" of longer teeth, seven per side in the skull and about the same number in the corresponding part of the lower jaw. Further back, there are at least twenty-two teeth per upper jaw side in the maxilla, while the entire lower jaw side carries thirty-two teeth in the dentary bone. The upper jaw shows a prominent kink just behind the rosette, protruding to below; this convexly curved part of the maxilla has the longest teeth of the entire skull. The skull is reminiscent of that of crocodilians that eat mainly fish. The internal bone shelves of the maxillae meet each other over a long distance, forming a closed front palate rigidifying the snout. The nostrils are long, narrow and horizontally positioned; the same is true of the larger antorbital fenestra. The rear of the skull is poorly known but a short quadrate, separated from the quadratojugal by a large ''foramen quadraticum'', shows it must have been low. The lower jaws are very elongated and narrow, forming a rigid structure as their dentaries touch each other at the midline, reinforcing the mandible against torsional forces.〔 The neck is relatively short but well-muscled as shown by strong epipophyses. There are about sixteen back vertebrae. ''Suchomimus'' had neural spines, blade-shaped upward extensions on the vertebrae, which are elongated at the rear back. Those of the five sacral vertebrae are the longest. To behind, the elongation continues until the middle tail. The spines may have held up some kind of low crest or sail of skin that was highest over its hips, lower and extending further to the back than that of ''Spinosaurus''.〔 The furcula is V-shaped and indicates a high and narrow trunk.〔 The humerus is very strongly built, only equalled in size among Theropoda by that of ''Megalosaurus'' and ''Torvosaurus''. Accordingly, the ulna of the lower arm is well-developed with an enormous olecranon, upper process, that is set-off from the shaft, an exceptional trait shared with ''Baryonyx''. The heavy arm musculature powered sizeable hand claws, that of the thumb being the largest with a length of nineteenth centimetres.〔 In the pelvis, the ilium is high. The pubic bone has a front surface that is wider than the side surface. The thighbone is straight and robust, 1075 millimetres long in the holotype. Its lesser trochanter is markedly plate-like.〔 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「Suchomimus」の詳細全文を読む スポンサード リンク
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