the lower stage of the middle section of the Carboniferous system (period). It was differentiated by S. V. Semikhatova in 1934 on the territory of the Bashkir ASSR. In a typical cross section, it is composed of limestone with a characteristic complex of foraminifers (Pseudostaffella antiqua Dut. and others) and brachiopods (Choristites bisulcatiformis Semid. and others). In the USSR the Bashkirian Stage is widespread in the Urals, Timan, the Volga Region, the Don basin, and Middle Asia. In Western Europe the upper parts of the Namurian and the lower parts of the Westphalian series, in the local stratigraphic system, correspond to the Bashkirian Stage.