Hierarchy classification:

1. top of the aat hierarchies
2. Styles and Periods Facet
3. Styles and Periods (hierarchy name)
4. [styles, periods, and cultures by general era]
5. geologic time scale
6. Phanerozoic

Narrower term/s

• Cambrian
• Ordovician
• Silurian
• Devonian
• Carboniferous
• Permian

Anotations

Scope note:

The first era of the Phanerozoic. It extends from 542 to 251 million years ago and includes the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian periods .The Paleozoic begins with the Cambrian explosion, an unparallelled diversification of organisms, and ends with the Permian extinction, the largest mass extinction in Earth's history. It precedes the Mesozoic era.