Britannica
Sources used in this answer
- A Journey Through Time Since the Precambrian - Paleogene Period: 66 million to 23 million years ago, and Neogene Period: 23 million to 2.6 million years ago
- Neogene Period
- Paleogene Period
- Cenozoic Era
- A Journey Through Time Since the Precambrian - Quaternary Period: 2.6 million years ago to the present
Which periods make up the Cenozoic Era?
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The Cenozoic Era is internationally recognized as being composed of three distinct periods:1
- Paleogene Period (66 million to 23 million years ago): This period is divided into the Paleocene, Eocene, and Oligocene epochs.231
- Neogene Period (23 million to 2.6 million years ago): This period includes the Miocene and Pliocene epochs.241
- Quaternary Period (2.6 million years ago to the present): This period encompasses the Pleistocene and Holocene epochs.15
While these three periods are the current standard, you may encounter older literature that divides the Cenozoic Era into the Tertiary Period (covering the time now assigned to the Paleogene and Neogene) and the Quaternary Period. The use of the Paleogene and Neogene designations has become increasingly widespread to replace the now-obsolete Tertiary classification.431