关键词: 恐龙, 骨组织, 血细胞

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