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When did the Paleozoic Era begin and end?
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geologic history of Earth
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The Paleozoic Era, a major interval of geologic time, began 538.8 million years ago and ended approximately 252 million years ago.1
The era commenced with the Cambrian explosion, a period marked by an extraordinary diversification of marine life, and concluded with the end-Permian extinction, which stands as the most significant mass extinction event in the history of Earth.1