A Russian stage (311.7–309.2 Ma ago) in the Pennsylvanian epoch, preceded by the Melekesskian (Bashkirian epoch) and followed by the Kashirskian.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。