本文是利用扫描电子显微镜对陆栖恐龙tvrannosaurid与海栖渐增mosasaurid”牙齿结构进行的比较解剖学研究。化石采自加拿大RedDeerhiverValley上白里统Horse－shoeCanyon组。通过研究地层中出现的生物化石，特别是动物牙齿的组织结构，可以了解动物为了适应生活环境而发生的进化过程，也可以推测它们的系统发育关系。tyrannosaund与mosas。id都拥有锥状的同形齿，牙齿侧向扁平，且略向后弯曲。研究结果确认了tyrannosaurid的牙齿由于薄层的无柱釉质bPrismaticenamel）向齿质的侵人而造成许多的凹凸构造，此锯齿状构造沿着牙齿的前后缘，由牙齿的顶端分布至基部。因此tyrannosaurid的牙齿呈现着锐利的切缘；在这些凹凸状切缘的沟与小窝的深部可观察到有机物的沉积。但是类似的锯齿状构造只能在齿冠呈钝圆状的mosasaurid牙齿的基部附近观察到。我们以扫描电子显微镜（SEM）检索，确认两爬行类的齿质皆是属于中间型的真性齿质（intermediatetypeorthodentine）；所谓orthodentine即是细管齿质（tubulardentine）。tyrannosaurid的真性齿质的齿质小管只在齿质一釉质相接处Uentino—enamaljunction）附近放散出规则性的分歧与末枝。但mosasaurid的真性齿质的齿质J。管，在齿质的中间层与表层中，呈现着由复杂 This article is a comparative anatomical study of the tooth structure of terrestrial dinosaur tvrannosaurid and maritimus mosasaurid using scanning electron microscopy.The fossils were collected from the Upper-Brevis Horse-shoeCanyon group in RedDeerhiverValley, Canada.By studying the biological fossils in the strata, Especially the structure of animal teeth can understand the evolution of animals in order to adapt to the evolution of the living environment can also be speculated that their phylogenetic relationship.tyrannosaund and mosas.id have a cone-shaped teeth, lateral flattened teeth, and slightly The results of the study confirmed that tyrannosaurid’s teeth caused many indented structures due to invaginations of the dentin due to the thin, pillarless enamel bPrismaticenamel, distributed along the anterior and posterior edges of the teeth from the tip of the tooth to The tyrannosaurid’s teeth thus show a sharp cut edge; organic deposits can be observed at the valleys and pits of these concave-convex cut edges, but a similar jagged structure can only be found in a mosasaurid Observed near the base of the tooth. We used a scanning electron microscope ( SEM) to confirm that the two dentates are of intermediatetypeorthodentine, while the so-called orthodentine is tuberdentate.Tyrannosaurid ’ Eutectic junction near the enamel junction (Uentino-enamaljunction), regular disagreement with the distal branch, but mosasaurid’s true dentine denture J. Tube, in the middle layer of dentin and the surface, showing a complex