The discovery of the conchstracan fossils in Jiufotang Formation and Shahai Formation of Luanping Basin, north Hebei Province, and discussion of established stage of the land facies strata

In 2007 and 2008, abundant chonchostracan fossils were collected from Cretaceus Jiufotang Formation and Shahai Formation at Shanwan Village, Yangshugou Village, Xiaoqiaomugou Village, and Deshengling Village in Luanping County, Hebei Province. The conchostracan fossils are divided into 6 genera and 26 species, including one new genus and 22 new species. According to the standard of an erected stratotype, many methods were used. The authors divided the section into three lithologic units, and erected five conchostracan biostratigraphic assemblages. Therefore, it is suggested that the occurrence of conchostracan Eosestheria fuxinensis and Eosestheria jiufotangensis should be regarded as the indication of the bottom boundary.At the same time, the land facies Stage of the Jurassic and Cretaceous strata is established as Sanbaoying Stage, Yushuxia Stage, Zhangjiagou Stage, Liying Stage, Yaoziliang Stage, Qinghemen Stage, Haizhou Stage, and Sunjiawan Stage in the Northern Hebei Province and Westhern Liaoning Province, China.