摘要
This study is based on both a generic and species level investigation of the individual size of the latest Permian conodont Neogondolella Pa elements collected from Meishan Section A, Changxing, Zhejiang Province. In this study, an obvious size reduction of Neogondolella Pa elements within bed 24e of the upper Changxing Limestone is recognized. The size variation of the Neogon- dolella occurs simultaneously with some important events including the negative shift of δ 13C, change in the ratio of the abundance of cyanobacterial biomarkers versus that of other general bacterial biomarkers and the shallowing of the sea water. Through the investigation of the paleoenvironmental changes and the analysis of the paleoecology of the conodont genus Neogondolella, the authors propose that the major factors for the size reduction of species of the conodont genus Neogondolella are food shortages caused by the mass extinction, the shallowing of the sea water as well as the in- crease in opacity of the sea water during the end Permian. The same phenomenon of Neogondolella size reduction is also observed in preliminary research from the same horizon at Shangsi Section, Sichuan Province. All the evidence suggests that there was a mass extinction that occurred at the horizon of bed 24e, and the evidence supports the viewpoint of a multi-phase mass extinction during the Permian and Triassic transition in South China.
This study is based on both a generic and species level investigation of theindividual size of the latest Permian conodont Neogondolella Pa elements collected from MeishanSection A, Changxing, Zhejiang Province. In this study, an obvious size reduction of NeogondolellaPa elements within bed 24e of the upper Changxing Limestone is recognized. The size variation of theNeogondolella occurs simultaneously with some important events including the negative shift ofδ^(13)C, change in the ratio of the abundance of cyanobacterial biomarkers versus that of othergeneral bacterial biomarkers and the shallowing of the sea water. Through the investigation of thepaleoenvironmental changes and the analysis of the paleoecology of the conodont genus Neogondolella,the authors propose that the major factors for the size reduction of species of the conodont genusNeogondolella are food shortages caused by the mass extinction, the shallowing of the sea water aswell as the increase in opacity of the sea water during the end Permian. The same phenomenon ofNeogondolella size reduction is also observed in preliminary research from the same horizon atShangsi Section, Sichuan Province. All the evidence suggests that there was a mass extinction thatoccurred at the horizon of bed 24e, and the evidence supports the viewpoint of a multi-phase massextinction during the Permian and Triassic transition in South China.
基金
supported by the National Natural Science Foundation of China(Grant No.40232025)
the GeoTurn Group of China University of Geosciences.
