Temperature: 18 °C
Atmospheric oxygen: 30%
The Cretaceous is the last period of the Mesozoic era, ending with a large mass extinction – the famous comet that destroyed the dinosaurs. It was a period with a relatively warm climate, resulting in high sea levels that created numerous shallow inland seas.
During the Cretaceous the South Atlantic Ocean opened. India separated from Madagascar and raced northward on a collision course with Eurasia. Notice that North America was connected to Europe, and that Australia was still joined to Antarctica.