Discovery of Qinghaiestheria from the Upper Jurassic Penglaizhen Formation in Sichuan, southwestern China

Abstract

The conchostracan Migransia sichuanensis Shen and Chen was described from the Upper Jurassic Penglaizhen Formation of the Sichuan Basin, southwestern China. It is now reassigned to the genus Qinghaiestheria Wang, which was originally described from the Upper Jurassic Hongshuigou Formation of the western Qaidam Basin, Qinghai Province. The occurrence of Qinghaiestheria from both formations supports the correlation between the Penglaizhen and Hongshuigou formations, and further suggests that the Yixian Formation of Liaoning Province is younger than these two formations. As the serration structure along the lower margins of growth lines has been considered as a taxonomic feature just for the genus or subgenus, the genus Qinghaiestheria is herein attributed to the family Fushunograptidae Wang instead of the family Afrograptidae Novojilov. And the genus Qinghaiestheria possibly lived in freshwater-brackish environments through comparison with conchostracans from the Middle Jurassic Great Estuarine Group of Scotland.