An epoch (270.6–260.4 Ma ago) in the Middle Permian of N. America, underlain by the Leonardian, overlain by the Ochoan, and roughly contemporaneous with the Ufimian and lower Kazanian stages.
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。