A stage (306.5–305 Ma ago) in the Pennsylvanian of N. America, underlain by the Desmoinesian, overlain by the Virgilian, and roughly contemporaneous with the Krevyakinskian and lower Chamovnicheskian stages of the Kasimovian series.
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。