Cretaceous Period

The Cretaceous Period is the third and final period of the Mesozoic Era, lasting from approximately 145 to 66 million years ago. It is known for being the last period of the age of dinosaurs, as well as the time when flowering plants (angiosperms) and modern groups of insects, birds, and mammals began to diversify.

Key Events and Characteristics

• Dinosaurs: The Cretaceous Period saw the peak diversity and dominance of dinosaurs. Iconic species such as Tyrannosaurus rex, Triceratops, and Velociraptor lived during this time.
• Flowering Plants: Angiosperms, or flowering plants, became widespread during the Cretaceous, eventually outcompeting many of the existing plant groups.
• Extinction Event: The Cretaceous-Paleogene (K-Pg) extinction event occurred at the end of the period, leading to the extinction of the non-avian dinosaurs, as well as many other plant and animal species.
• Geography: During the Cretaceous, the continents were still relatively close together, with a warm climate and high sea levels. This allowed for the formation of large inland seas and an abundance of marine life.
• Climate: The climate was generally warm, and there were no polar ice caps. However, there were fluctuations in temperature and sea levels throughout the period.

Study Guide

To study the Cretaceous Period, you should focus on the following key points:

1. Identify and describe the major groups of dinosaurs that lived during the Cretaceous Period.
2. Explain the significance of the rise of flowering plants and how they impacted the Earth's ecosystems.
3. Discuss the causes and effects of the Cretaceous-Paleogene extinction event.
4. Describe the geographic and climatic conditions during the Cretaceous Period and their influence on the diversity of life.
5. Compare and contrast the Cretaceous Period with the preceding and succeeding periods of the Mesozoic Era.

By understanding these key points, you will have a comprehensive knowledge of the Cretaceous Period and its importance in Earth's history.

[Cretaceous] Related Worksheets and Study Guides:

• Geologic timeScience • Eighth Grade