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:

The final period of the Paleozoic Era. The Permian Period began 298.9 million years ago and ended 252.2 million years ago, following the Carboniferous and preceding the Triassic. Glaciation was widespread in the early Permian, but the climate warmed throughout the period resulting in hot and dry conditions that caused a crisis in marine and terrestrial life.