Nonmarine ostracod fauna from the Lower Cretaceous Shinekhudag Formation (southwest Mongolia): taxonomy, biostratigraphy, and paleoecology

Abstract This work provides the detailed investigation (taxonomy, biostratigraphy, and paleoecology) of a nonmarine ostracod fauna from Shinekhudag Formation in Gobi–Altai area, southwest Mongolia. The samples two sections (Tsagaan Tsuvarga Oshih Hollow East) yielded various ostracods assigned to nine species belonging six genera: Cypridea verrucata Neustrueva, 1974, C. ihsienensis Hou, 1958, unicostata Galeeva, 1955, tumefacta Yumenia cf. Y. oriformis Scabriculocypris subscalara Zhang Chen Ye et al., 2003, ? Trapezoidella sp., Candona Vlakomia ulanense 1977. biostratigraphic application our taxonomic results suggests that age is Barremian–Aptian. In addition, shows strong affinities faunas northeast China potentially northwest China, providing evidence faunal exchanges between these regions new discovery indicates mid-Cretaceous (Albian) probably originated Mongolia at time deposition Formation. Two assemblages studied reflect different paleoenvironment settings have existed during deposition; Tsagaan Section represents shallow-littoral zone athalassic (inland) saline lake under arid climate, dominance cypridoideans East indicative ephemeral water bodies.