辽西白垩纪孙家湾组新发现恐龙牙齿化石

发布时间：2018-06-20 02:06

本文选题：恐龙 + 辽宁　；参考：《沈阳师范大学》2015年硕士论文

【摘要】：辽宁西部中生代孙家湾组是白垩纪中期一个重要的含恐龙化石地层。本文记述了产自该组的恐龙牙齿化石,分别代表了禽龙类、巨龙类和兽脚类三个恐龙类群,进一步丰富了孙家湾组的恐龙类群。禽龙类牙齿:齿冠磨蚀严重,仅保存有齿冠的基部,可能属于正常脱落的牙齿;齿冠宽大,中嵴强烈发育;基部两侧不发育锯齿;磨蚀面呈菱形,发育十字形主脊和微弱副脊。巨龙类牙齿:齿冠顶部保存,呈柱状;齿冠顶端有磨蚀面,代表了巨龙类的牙齿顶端咬合特点;齿冠横切面呈D型,唇侧面中嵴微弱发育。兽脚类牙齿:牙齿保存为齿冠的一段,靠近基部;牙齿大,齿冠的前后长度16.5mm;横切面呈椭圆形,长宽比1.8;齿冠前缘宽,后缘窄;后缘保存有锯齿,锯齿小,排列紧密,5毫米13-14个锯齿。这些牙齿,特别是禽龙类和巨龙类牙齿,符合之前的化石报道,可能归入双庙龙(Shuangmiaosaurus)和北方龙(Borealosaurus);进而支持了之前有关双庙龙作为禽龙类的论断。作为孙家湾组兽脚类恐龙牙齿化石的首次发现,该兽脚类牙齿可能代表了一类大型肉食性恐龙,进一步丰富了孙家湾组恐龙生物群的组成面貌。
[Abstract]:The Sunjiawan formation of Mesozoic in western Liaoning is an important dinosaur bearing fossil stratum in the middle Cretaceous. This paper describes the fossils of dinosaur teeth from this group, which represent three groups of dinosaurs, namely, Anosaurus, Giganosaurus and Carnopoda, which further enrich the Dinosaur Group of the Sunjiawan formation. Fowl dragon teeth: the tooth crown is worn seriously, only has the tooth crown base, may belong to the normal fall off tooth; the tooth crown is broad, the middle ridge strongly develops; the base both sides does not develop the sawtooth; the abrasion surface assumes the rhombus shape, develops the cross-shaped main ridge and the weak accessory ridge Dragon teeth: the top of the crown is preserved in columnar shape; the top of the crown has an erosion surface, which represents the occlusal characteristics of the tooth tip of the giant dragon; the transverse section of the tooth crown is D type, and the middle ridge of the lip develops weakly. A section of a tooth conserved as a crown near the base; a large tooth with a length of 16.5 mm before and after the crown; an elliptical transverse section with a aspect ratio of 1.8; the front edge of the tooth crown is wide and the rear edge is narrow; the posterior edge is preserved with serrated, small serrated teeth. Closely arranged 5 mm 13-14 serrated. These teeth, especially the fowl and giant ones, fit in with previous fossil reports and may be classified as Shuangmiaosaurus) and Borealosaurus, which in turn underpin previous claims that Tsangmiaosaurus is an avian dragon. As the first discovery of the fossils of the dinosaur teeth of the Sunjiawan formation, the teeth of the phylopod may represent a large carnivorous dinosaur and further enrich the composition of the dinosaur biota of the Sunjiawan formation.
【学位授予单位】：沈阳师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q915

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