Cretaceous Period
The Cretaceous Period is the third and final period of the Mesozoic Era, spanning approximately 79 million years from around 145 to 66 million years ago. It is known for being the period in which dinosaurs reached their peak diversity and dominated the Earth's ecosystems.
Geology and Climate
During the Cretaceous Period, the Earth's continents were still in the process of breaking apart and shifting into their modern positions. The supercontinent Pangaea continued to break up, leading to the formation of the Atlantic Ocean. The climate was generally warm and mild, with higher global sea levels and a relatively stable greenhouse effect.
Life During the Cretaceous
The Cretaceous is best known for its diverse and abundant life forms, particularly the dinosaurs. Some of the most well-known dinosaurs, such as Tyrannosaurus rex, Triceratops, and Ankylosaurus, lived during this period. Other notable groups of organisms that thrived during the Cretaceous include marine reptiles like mosasaurs and plesiosaurs, as well as early birds and flowering plants.
Study Guide
- What are the major geologic events that occurred during the Cretaceous Period?
- Describe the climate of the Cretaceous Period and how it may have influenced the evolution of life.
- Identify and describe at least three iconic dinosaur species that lived during the Cretaceous.
- Discuss the significance of the Cretaceous Period in the evolutionary history of flowering plants.
- Explain how the breakup of Pangaea during the Cretaceous impacted global geography and ecosystems.
