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''Haestasaurus'' is a genus of herbivorous sauropod dinosaur, belonging to the Macronaria, that during the Early Cretaceous lived in the area of present-day England. The only species is ''Haestasaurus becklesii''.〔Upchurch P., Mannion P.D., Taylor M.P., 2015, "The Anatomy and Phylogenetic Relationships of “''Pelorosaurus''“ ''becklesii'' (Neosauropoda, Macronaria) from the Early Cretaceous of England", ''PLoS ONE'' 10(6): e0125819. 〕 ==Description== As a sauropod, ''Haestasaurus'' would have been a large quadrupedal long-necked dinosaur. Little information is available about the specifics of its build because only a forelimb is known of the animal. An indication of the size of ''Haestasaurus'' is given by the length of the forelimb elements. The humerus is 599 millimetres long, the ulna 421 millimetres and the radius, situated next to the ulna in the lower arm, has a length of 404 millimetres.〔 A 2015 study found several unique anatomical traits (autapomorphies) distinguishing ''Haestasaurus'' from related species. The inner front corner of the humerus is protruding, forming a ''processus entepicondylaris anterior''. Between the front condyles of the lower humerus two small vertical ridges are present. The upper surface of the radius has, measured from front to rear, its largest width along the outer rim, which edge is nearly straight instead of strongly convex. The lower front of the radius is lightly concave between outer and inner ridges. A unique combination is present of a robust ulna, its upper surface having a width equalling more than 40% of the shaft length, with a slender radius having an upper width of less than 30% of total length.〔 A rock associated with the forelimb, NHMUK R1868, was the first specimen known preserving parts of the sauropod skin. These probably are not impressions as the visible surface of the scales is convex, but natural casts. An area of 215 by 195 millimetres has been preserved. It shows non-overlapping hexagonal scales with a diameter of between ten and twenty-five millimetres. The scales gradually decrease in size, perhaps towards the elbow, to provide it greater flexibility. The scales strongly resemble skin impressions of later sauropod finds.〔 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「Haestasaurus」の詳細全文を読む スポンサード リンク
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