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,
Lake Parime the Takutu Basin or the Takutu Formation, dates back to the late Paleozoic, roughly 250 million years ago, and the basin connected with the Atlantic via the Takutu Graben. The geologic history of the Takutu Graben is characterized by one phase of volcanic activity and three depositional phases of sedimentary rocks. Rifting (due to divergent tectonic plate movements) occurred in "a lake or delta environment" in the Late Triassic to Early Jurassic periods, between 200 million and one hundred and fifty million years ago. Starting around 66,000 years ago, sea level rise and more humid conditions created flooded zones north