标题：The brackish-water bivalve Waagenoperna from the Lower Jurassic Badaowan Formation of the Junggar Basin and its palaeoenvironmental and palaeogeographic significance
摘要：AbstractThe brackish-water bivalveWaagenopernaTokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features recorded in the field indicate that it occurs in autochthonous or parautochthonous assemblages. The autecology ofWaagenopernatherefore yields information on the palaeoenvironment of the area. The restriction ofWaagenopernato marine and brackish-water settings suggests that the sea water once reached these areas during the Sinemurian. This paper discusses the palaeogeographic implications and suggests an ingression of the sea water from the west to the western and southern part of the Junggar Basin. Additionally, the twoWaagenopernaspecies collected from the Haojiagou section in the Junggar Basin are taxonomically documented.Graphical abstractDisplay OmittedHighlights► The palaeogeographic implications of brackish-water bivalveWaagenopernain Junggar Basin are discussed. ► An ingression of sea water from the west to the Junggar Basin in Sinemurian is suggested. ► TwoWaagenopernaspecies collected from the Haojiagou section in the Junggar Basin are taxonomically documented.
