Cretaceous

The Cretaceous (145-66 million years ago) is the last geologic period of the Mesozoic era; it follows the Jurassic period and is followed by the Paleogene period. The Cretaceous was the peak of the dinosaurs reign and broadly exhibited great biodiversity. A warm climate, resulting in high sea levels created shallow inland seas that were populated with now extinct marine reptiles and ammonites. During this time, new groups of mammals and birds, as well as flowering plants in tandem with insects such as bees appeared. The apex predators were the dinosaurs, which were at their most diverse stage and included the most infamous species such as the tyrannosaurus. Flying Pterosaurs were common in the early and middle Cretaceous, but declined for poorly understood reasons. The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene extinction event which among a number of factors included a giant meteorite impact that would have significantly blocked sunlight and hence cut the bottom out of the food chain via photosynthesising plants. Many groups including non-avian dinosaurs, pterosaurs and large marine reptiles died out.