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''Sinosauropteryx'' (meaning "Chinese reptilian wing", ) is a compsognathid dinosaur. Described in 1996, it was the first dinosaur taxon outside of Avialae (birds and their immediate relatives) to be found with evidence of feathers. It was covered with a coat of very simple filament-like feathers. Structures that indicate colouration have also been preserved in some of its feathers, which makes ''Sinosauropteryx'' the first non-avialian dinosaurs where colouration has been determined. The colouration includes a reddish and light banded tail. Some contention has arisen with an alternative interpretation of the filamentous impression as remains of collagen fibres, but this has not been widely accepted. ''Sinosauropteryx'' was a small theropod with an unusually long tail and short arms. The longest known specimen reaches up to in length, with an estimated weight of It was a close relative of the similar but older genus ''Compsognathus'', both genera belonging to the family Compsognathidae. Only one species of ''Sinosauropteryx'' has been named: ''S. prima'', meaning "first" in reference to its status as the first feathered non-avialian dinosaur species discovered. Three specimens have been described. The third specimen previously assigned to this genus represents either a second, as-yet unnamed species or a distinct, related genus. ''Sinosauropteryx'' lived in what is now northeastern China during the early Cretaceous period. It was among the first dinosaurs discovered from the Yixian Formation in Liaoning Province, and was a member of the Jehol Biota. Well-preserved fossils of this species illustrate many aspects of its biology, such as its diet and reproduction. ==Description== ''Sinosauropteryx'' was a small bipedal theropod, noted for its short arms, large first finger (thumbs), and long tail. The taxon includes some of the smallest known adult non-avian theropod specimens, with the holotype specimen measuring only in length, including the tail. However, this individual was relatively young. The longest known specimen reaches up to in length, with an estimated weight of . ''Sinosauropteryx'' was anatomically similar to ''Compsognathus'', differing from its European relatives in its proportions. The skull of ''Sinosauropteryx'' was 15% longer than its thigh bones, unlike in ''Compsognathus'', where the skull and thigh bones are approximately equivalent in length. The arms of ''Sinosauropteryx'' (humerus and radius) were only 30% the length of its legs (thigh bone and shin), compared to 40% in ''Compsognathus''.〔 Additionally, ''Sinosauropteryx'' had several features unique among all other theropods. It had 64 vertebrae in its tail. This high number made its tail the longest relative to body length of any theropod.〔 Its hands were long compared to its arms, about 84% to 91% of the length of the rest of the arm (humerus and radius), and half the length of the foot. The first and second digits were about the same length, with a large claw on the first digit.〔 The first fingers were large, being both longer and thicker than either of the bones of the forearm.〔 The teeth differed slightly (they were heterodont) based on position: those near the tips of the upper jaws (on the premaxillae) were slender and lacked serrations, while those behind them (on the maxillae) were serrated and laterally compressed. The teeth of the lower jaws were similarly differentiated.〔 A pigmented area in the abdomen of the holotype has been suggested as possible traces of organs,〔 and was interpreted as the liver by John Ruben and colleagues, which they described as part of a crocodilian-like "hepatic piston" respiratory system. A later study, while agreeing that the pigmented area represented something originally inside the body, found no defined structure and noted that any organs would have been distorted by the processes that flattened the skeleton into an essentially two-dimensional form.〔 Dark pigment is also present in the eye region of the holotype and another specimen.〔 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「Sinosauropteryx」の詳細全文を読む スポンサード リンク
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