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
7. Paleozoic

Anotations

Scope note:

An interval of the Paleozoic Era that followed the Silurian Period and preceded the Carboniferous Period, spanning between about 419.2 million and 358.9 million years ago. This period featured diverse and abundant aquatic life. Forests and marine organisms known as ammonites appeared early in the Devonian, and later amphibians appeared, the first vertebrates on land.