An epoch (99.6–65.5 Ma ago) in the N. American Upper Cretaceous, underlain by the Comanchean, and overlain by the Puercan (Palaeocene).
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。