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. Cenozoic

Narrower term/s

• Paleocene
• Eocene
• Oligocene

Anotations

Scope note:

Oldest of the three divisions of the Cenozoic Era spanning between 66 million and 23 million years ago. It includes the Paleocene, Eocene and the Oligocene epochs. This period was formerly considered a part of the Tertiary.