Cretaceous is the last period of Triassic, which is the stage from prosperity to complete extinction of dinosaurs. During this period, there are a lot of chalk in the deep-sea deposits in Europe, which is called "Cretaceous", so Cretaceous is famous. Chirosaurus perished in the Cretaceous. However, cimurosaurus, hornnose and horned dragons made rapid progress in the late Cretaceous, especially horned dragons. Although they suddenly appeared on the earth in the late Cretaceous, they evolved rich and colorful varieties in a very short period of time. Cretaceous dinosaur species reached their heyday, and the most well-known Tyrannosaurus rex was a large carnivore that suddenly appeared on the continent.

At the end of Cretaceous, organisms on the earth experienced an important extinction: many vertebrates in the dominant position on the ground disappeared, and dinosaurs completely perished; About half of the green plants and other predators disappeared at the same time. In the final analysis, what caused the sudden extinction of dinosaurs and a large number of organisms? This problem has always been an unsolved mystery in the history of geological development.