A stage in the Pennsylvanian epoch dated at 311.7–306.5 Ma ago (Int. Commission on Stratigraphy, 2004), comprising the Vereiskian, Kashirskian, Podolskian, and Myachkovskian Russian stages, preceded by the Bashkirian and followed by the Kasimovian epochs. It is roughly contemporaneous with the Atokan and Desmoinesian (N. America) and the Westphalian B, C, and D plus the lowermost Stephanian (western Europe).