四川自贡地区晚侏罗世剑龙类皮肤印痕化石新观察

Stegosaurian skin impressions from the Upper Jurassic Shangshaximiao Formation,Zigong,Sichuan,China:A new observation

重新观察了四川自贡晚侏罗世上沙溪庙组巨棘龙皮肤印痕化石。化石材料清楚地显示了巨棘龙体被鳞片。这些鳞片总体镶嵌排列成网状。大多数鳞片呈五边形,少数呈四边形或六边形。鳞片之间以沟缝相接。小鳞片中散布有少量五边形或六边形的大鳞片,每枚大鳞片被13～14枚鳞片所环绕。鳞片表面粗糙,不存在"瘤状小突",有条索状隆突。条索状隆突可降低环境光线造成的眩光,降低鳞片表面整体亮度水平。据原始埋藏的位置和鳞片的分布推测,四川巨棘龙皮肤印痕化石的身体位置可能为前肢的肘关节及其邻近的上臂、体侧的皮肤。

A skin impression fossil of Gigontspinosaurus siehuanensis was found in the Upper Jurassic Shangshaximiao Formation in Zigong, Sichuan. The fossil, preserved on the dorsal face of the left shoulder, clearly shows scales of Gigantspinosaurus sichuanensis. These scales are generally arranged as a net, and most of them are pentagonal, a few being quadrilateral and hexagonal. The naximum inner radius of most scales range from 5.7 to 9.2 mm, The scales are connected with each other by grooves. Scattered within small scales are a few pentagonal or hexagonal large scales, with each large scale surrounded by 13-14 scales. The surface of the scales is rough with string-like ridges. The stringy ridge on the scales made the surface of the scales uneven and thus may reduce the glare caused by reflected light. Based on the primary burial location and distribution of the scales, the authors believe that the skin impression fossil of Gigantspinosaurus siehuanensis is from the elbow of the forelimb, relevant upper arm and lateral area of the body.