New data of early Late Ordovician chitinozoans from the Miaopo Formation at Jieling, Yichang, central China

Abstract

Chitinozoans from the uppermost Darriwilian–lower Sandbian Miaopo Formation at Jieling of western Hubei Province are reported, for the first time, including 30 species of 14 genera from 10 collections which are much more diverse and abundant than previously known. Two chitinozoan assemblages are recognized: the Laufeldochitina cf. striata Assemblage and the Eisenackitina cf. rhenana Assemblage. The L. cf. striata Assemblage is correlative to the upper Hustedograptus teretiusculus graptolite biozone. The base of the E. cf. rhenana Assemblage coincides with the base of the Nemagraptus gracilis graptolite biozone, indicating that E. cf. rhenana has the potential for recognizing the base of Upper Ordovician.