Preliminary Taphonomic Study On Dinosaur Fossils In Yujingzi Basin, Gansu Province

The Lower Cretaceous deposits are quite developed in Yujingzi basin, Gansu, yielding abundant fossils, especially dinosaur fossils. Up till now, the following dinosaurs have been discovered and identified, they are: the large-sized Peishanosaurus philemy, Suzhousaurus megatherioides ; the moderate- and small-sized Equijubus normani, Chiayusaurus lacustris and Auroraceratops rugosus.Through the observation, analysis and statistical study on the fossils of Peishanosaurus philemy, Suzhousaurus megatherioides, we found that these fossils are seriously broken and incompletely perserved, the differential weathering is severe, missing skull fossils, poor articulated, with distinct abrasion signs on fossil surfaces. By the way, there are quite differences between the surrounding rocks and fossil-bearing layers. All these features indicate that the living environment of the two dinosaurs above was far from the , buried environment, belong to heterochthonous burial, the transportation force might be fluvial current. However, the fossils of Equijubus Norman, Chiayusaurus lacustris and Auroraceratops rugosus are well preserved, less broken, good articulated, without differential weathering, the fossil surfaces smooth, partially with enamel spots, without abrasion signs. All these characteristics imply that the buied site of these moderate- and small-sized dinosaurs is not far from their living environment, belonging to an autochthonous burial under the condition of rapid sedimentation.The taphonomic study on dinosaur fossils could provide good evidence for dealing with the paleoenvironment, paleoecology and paleoclimate in the study area.