Abstract: Well preserved blood vessels and resemble blood corpuscles have been observed in the bone tissue of a therizinosauroid dinosaur from the lower part of the Yixian Formation(Early Cretaceous)in Liaoning Province, northeast China. The fossil therizinosauroid dinosaur is consisting of a section of vertebral column, and fragmentary limb bones. Brownish filamentous integumentary impression occurred around the limb bones. The integumentary filaments are unbranched, about 0.1mm wide and 50～60mm long. At a longitudinal section of the dinosaur's humerus bone, brownish blood vessels have been observed under the microscope. Some blood vessels contained brownish small rounded bodies; they often scattered or gathered along the blood vessels. The occurrence, shape and size of the small bodies indicate that they are possibly remains of the dinosaur's blood cells. The vascularity of the bone tissue, have been measured by using image analysis method, the relatively high vascularity of the bone tissue indicates a relatively high metabolic rate of this dinosaur. The histological features of the bone tissue and the filamentous integuments that possibly served as body heating insulation, demonstrate that the animal might be endothermal.

Key words: Dinosaur, bone tissue, blood cell

摘要： 在我国辽宁北票下白垩统义县组下部地层中出土的北票龙(Beipiaosaurus inexpectus)化石由部分椎骨和肢骨碎片构成，其中保存有血管和类似血细胞的结构。在肢骨周围有褐色细丝状的皮肤衍生物的印痕。细丝状皮肤衍生物无分枝，大约0.1mm宽，50～60mm长。在光学显微镜下观察到其肱骨的纵切面上有褐色血管结构，一些管腔中有褐色小圆球，它们沿着管腔分布。这些小圆球的形状和大小显示它们有可能是恐龙血细胞的遗迹。另外，图像分析法结果显示北票龙骨组织有较高的血管密度，表示它具有较高的新陈代谢率。从骨组织特征及作为体表隔热层的细丝状皮肤衍生物的存在来看，北票龙可能为恒温动物。

关键词: 恐龙, 骨组织, 血细胞