Cretaceous Cretaceous The Cretaceous (, ) is a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago (mya) to the beginning of the Paleogene Period mya. It is the last period of the Mesozoic Era, and the longest period of the Phanerozoic Eon. The Cretaceous Period is usually abbreviated K, for its German translation "Kreide" (chalk, "creta" in Latin). The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles,
Middle Triassic Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between Ma and Ma (million years ago). The Middle Triassic is divided into the Anisian and Ladinian ages or stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of rock strata with approximately Middle Triassic age, found in western Europe. During this time there were no flowering plants, but instead