Published online by Cambridge University Press: 14 July 2015
The Namurian Tsingyuan Formation from Ningxia, China, is divided into three members. The remarkably well-preserved gastropods from the Tsingyuan Formation belong to three assemblages: the Angyomphalus longicostatus—Glabrocingulum tongxinensis assemblage from the Lower Member; an assemblage of some siliceous Bellerophon sp., and Naticopsis sp. from the Middle Member; and the Euphemites hindi—Turbonitella semisulcatus assemblage from the Upper Member. Based on the associated ammonoids and conodonts, these assemblages are considered equivalent to the Eumorphoceras, Homoceras2-Reticuloceras1 and Reticuloceras2 zones of West Europe respectively.