河南西峡地区晚白垩世介形虫的发现及其地层意义

Discovery of Late Cretaceous ostracods in Xixia,Henan,China,and its stratigraphic significance

2005年在河南西峡含恐龙蛋层中首次发现介形虫化石,产自红山水库-丹水剖面上白垩统赵营组下段64层,是以Eucypris-Mongolocypris-Cypridea-Talicypridea为特征的介形虫化石组合,由12属20余种组成。其中Talicypridea是中国、蒙古和东亚晚白垩世最典型的化石,在非洲刚果及南美阿根廷的晚白垩世地层中也有分布,因此赵营组的时代无疑应归属为晚白垩世。赵营组介形虫化石的新发现,为地层的划分对比、沉积环境的演变和盆地的演化研究提供了重要的依据。

Ostracods were for the first time found in strata containing dinosaur eggs in Xixia, Henan. These ostracods occur in bed 64 in the Lower Member of the Upper Cretaceous Zhaoying Formation at the Hongshan Reservoir-Danshui section. One ostracod assemblage has been recognized, which is characterized by Eucypris-Mongolocypris-Cypridea-Tcdicypridea and consists of 12 genera and 20 species. In this assemblage, most species were previously detected in the Late Cretaceous, of which Tcdicypridea is the most typical Late Cretaceous ostracod genus in China ,Mongolia and East Asia and is also distributed in Late Cretaceous strata of the Congo of Africa and Argentina of South America. So the age of the Zhaoying Formation should be undoubtedly assigned to Late Cretaceous. The discovery of ostracods in the Zhaoying Formation furnishes important evidence for studying the stratigraphical division and correlation, evolution of the sedimentary environment and evolution of basins.