Late Carboniferous (Pennsylvanian) ostracods from East Junggar in Xinjiang, northwestern China

Abstract Late Carboniferous (Pennsylvanian) ostracods are described from East Junggar in Xinjiang Uygur Autonomous Region (referred here as Xinjiang) of northwestern China. Twenty-one species belonging to 11 genera are recognized. Among them, two are new, Acratia xinjiangensis sp. nov. and Healdianella shiqianensis sp. nov. These species can be referred to the Ostracod Assemblage‐3 (OA-3) of the Shiqiantan Formation, and together with zircon U-P dating suggest a probable Moscovian–Kasimovian (middle–late Pennsylvanian) age for the unit. The OA-3 found in the limestones of the Shiqiantan Formation inhabited in open oceanic island arc context that is ecologically equivalent to the Eifelian Mega-Assemblage, and incorporated smooth-podocopid associations. The Shiqiantan Formation OA-3 thus implies a foreshore to offshore environmental transition within a post-collision rift basin. Zhengjiang Luo [luozj@petrochina.com.cn], Rui Wang [Wangrui@petrochina.com.cn], Aliya Amuti [alya@petrochina.com.cn] and Yong Deng [dengyong@petrochina.com.cn], PetroChina Xinjiang Oilfield Company Research Institute of Experiment and Detection and Joint Laboratory of Stratigraphy and Palaeontology, Xinjiang Oilfield Company, Nanjing Institute of Geology and Palaeontology, CAS, Karamay, Xinjiang 834000, PR China Yucong Sun [18635935938@163.com], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, PR China; Wenkun Qie [wkqie@nigpas.ac.cn] and Junjun Song [jjsong@nigpas.ac.cn] State Key Laboratory of Paleobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, PR China.