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Which periods make up the Mesozoic Era?
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geologic history of Earth
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The Mesozoic Era, often referred to as the age of the dinosaurs, is the second of Earth's three major geologic eras within the Phanerozoic Eon. Spanning from 252.2 million to 66 million years ago, it is divided into three distinct periods, listed here from oldest to youngest:
- Triassic Period: Lasting from approximately 252 to 201 million years ago, this period marked the beginning of major biological and geological transitions, including the initial rifting of the supercontinent Pangea and the appearance of the first dinosaurs and mammals.123
- Jurassic Period: Following the Triassic, this period is well known for the continued diversification and dominance of dinosaurs.2
- Cretaceous Period: The final period of the Mesozoic, which concluded 66 million years ago with a mass extinction event that resulted in the demise of the dinosaurs.2