CretaceousWiktionary 原文中文来自 ECDICTadj.白垩系的，白垩纪的n.白垩纪，白垩系词源说明Specific use of cretaceous.释义（英文）专有名词 Proper noun(geology) The geologic period within the Mesozoic era that comprises lower and upper epochs from about 146 to 66 million years ago.词族派生词（1）end-Cretaceous