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

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-Talicypridea and consists of 12 genera and 20 species. In this assemblage, most species were previously detected in the Late Cretaceous, of which Talicypridea 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.