DISCOVERY OF TRILOBITES FROM THE XIHAOPING MEMBER （LOWER CAMBRIAN） OF THE DENGYING FORMATION IN FANGXIAN COUNTY HUBEI PROVINCE

After the discovery of the Xihaoping Fauna in Fangxian, Hubei, now there are three opinions on the age of the Xihaoping Fauna: （1）the fauna is equivalent to fossil assemblages Ⅰ and Ⅱ of the Meishucunian Stage, （2） it is equivalent to fossil assemblage Ⅱ of the Meishucunian Stage, and （3） its age is later than the Meishucunian. To solve this problem, the author studied related sections in Fangxian and found that trilobite fossils （Plate Ⅳ） coexist with small shelly fossils. According to these fossils, the Xihaoping Fauna can be correlated with the Upper Atdabanian （Adyshevitheca Zone in the upper part of the Shabaktin Formation） in Maly Karatau, Kazakhstan, the Comley limestone in Comley, England, and the Callavia Zone in the Weymouth Formation, Avalon, North America. In China, the Xihaoping Fauna has been found to coexist with trilobites Eoredlichia, Mianxiandiscus etc. in Zhenba, Shaanxi. In Wush （Tarim）, Xinjiang, the Xihaoping Fauna occur together with trilobite fragments and protoconodonts such as Amphigeisina, Gapparodus, Jiangshanodus and Xinjiangodus. So the geological age of the Xihaoping Fauna should be Late Qiong-zhusian （Early Cambrian）.