The Cretaceous Period was the last period of the Mesozoic Era. Huge and diverse creatures began to evolve. At the begining, creatures were much like that of the last period, the Jurassic Period. But soon things began to change. Animals, such as the Stegosaurs like the famous Stegosaurus began to become much more rare. More andvanced species appered. Snakes and turtles really started looking like they look like today. Life was at it's fullest. But around 80 million years ago things started to change. Events like extreme climates and poisoned air by volcanic activity started to deminish the number of species of certain animals including dinosaurs. Then about 65 million years ago, a meteorite the size of Mt. Everest (about 10 km wide) struck the earth. Shortly afterwards, all non-avian dinosaurs vanished, along with pterosaurs, plesiosaurs, moasosaurs, and some reptiles and birds. These events were called the K.T Extinction event and ended this period in earths history.It is the youngest period of the Mesozoic Era, and at 80 million years long, the longest period of the Phanerozoic Eon. The end of the Cretaceous defines the boundary between the Mesozoic and Cenozoic eras. In many languages this period is known as "chalk period".
The Cretaceous was a period with a relatively warm climate and high eustatic sea level. The oceans and seas were populated with now extinct marine reptiles, ammonites and rudists; and the land by Dinosaurs. At the same time, new groups of mammals and birds as well as flowering plants appeared.
It should be noted that the KT extinction event not only served as the end of the age of dinosaurs and or mezasoic era but it also gave rise too the rise of the smartest creatures ever to live on earth mammals there control over the world still goes on today.
Postitsion in The Timeline Of Earths History
The Cretaceous started 144 million years ago and ended 65 million years ago. Because it is the longest period, it is seperated into two epochs, the Upper and Lower Cretaceous