Cretaceous 白垩纪
The Cretaceous (pronunciation: , krə-TAY-shəs), derived from the Latin "creta" (chalk), usually abbreviated K for its German translation Kreide (chalk), is a geologic period and system from 145 ± 4 to 66 million years (Ma) ago. In the geologic timescale, the Cretaceous follows the Jurassic Period and is followed by the Paleogene Period of the Cenozoic Era. It is the last period of the Mesozoic Era, and, spanning 79 million years, the longest period of the Phanerozoic Eon.