The first period of the Cenozoic era, from about 65 to 1.8 million years ago, subdivided into the Palaeocene, Eocene, Oligocene, Miocene, and Pliocene epochs.
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。