The Cretaceous period began about
145 million years ago and ended 65 million
years ago with the extinction of the
dinosaurs. Flowering plants and modern
insects appeared.
Click on the dinosaurs for more information.
The Jurassic period began about 200 million
years ago and lasted about 55 million years.
Many new types of dinosaurs, mammals, and
reptiles emerged during the Jurassic,
including the plated dinosaurs and the
sauropods- heavy, long-necked dinosaurs that
walked on four legs.
