A Russian stage (300.5–299 Ma ago) and substage of the Gzhelian stage (Late Pennsylvanian sub-epoch), preceded by the Klazminskian and followed by the Asselian (Rotliegendes epoch of the Permian).
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。