Middle School
Worksheets
The Cretaceous Period
The last of the dinosaurs lived during a time called the Cretaceous period. This time period lasted from about 135 million to 65.5 million years ago. Some sources give the years of 146, 145, or 144 million to 65 million years ago.
In the Cretaceous period, the middle of North America was covered by a shallow sea. The Atlantic Ocean began opening up between Europe and North America as those continents rifted. Other continents that had begun pulling away from each other in the Jurassic continued drifting apart. India was an island by itself.
Evergreen trees, mosses, and ferns had been the main types of plants, but now in the Cretaceous, flowering plants appeared. Bees did, too. Hardwood trees like oaks and maples first appeared in the fossil record.
