Illinois State Museum

Missing Pieces - Forces of Change

globe graphic showing location of Illinois during the Cretaceous

Plate Tectonics
During this time, the continent of Pangea was formed and then broke apart. The continents moved around the globe to positions we would recognize today. India broke away from Africa and collided with Asia, pushing up the Himalayas and creating the Tibetan Plateau. The Rocky Mountains formed.

Evolution
Dinosaurs, birds, and mammals all evolved during this period.

Extinction
In the single greatest extinction event, which marked the end of the Permian Period 245 million years ago, 95 percent of marine species and 50 percent of all species on Earth disappeared. Another major extinction event 65 million years ago ended the Age of Dinosaurs.