NAMURIAN (LOWER CARBONIFEROUS) GASTROPOD ASSEMBLAGES FROM NINGXIA, CHINA

The Namurian Tsingyuan Formation from Ningxia, China, is divided into three members. The remarkably well-preserved gastropods from the Tsing yuan Formation belong to three assemblages: the Angyomphalus longicost alus-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 an d conodonts, these assemblages are considered equivalent to the Eumorp hoceras, Hamocerns(2)-Reticuloceras, and Reticuloceras(2) zones of Wes t Europe respectively.