Cretaceous

The Cretaceous was the third and last period of the Mesozoic Era, from about 145 to about 66 million years ago.

What the glossary says

Cretaceous — “The third and last geologic period of the Mesozoic Era, noted for the rise of flowering plants and the extinction of many groups at the end of the period; approximately 145 to 66 Ma.”

U.S. National Park Service, “Glossary of Paleontological Terms”. Quoted word for word. Courtesy of the National Park Service.

A flat world map about 90 million years ago drawn from a palaeogeographic elevation model: sand-coloured land, mid-blue shallow sea and dark-blue deep ocean. A band of shallow sea runs down the middle of North America. — Map built from dataThe world about 90 million years ago, as one model draws it: land in sand, shallow sea in mid-blue, deep ocean in dark blue. North America is not one piece of land. Drawn flat, so places near the poles look wider than they really are.Map data: Scotese & Wright (2018), PALEOMAP PaleoDEMs — rendered by triassicwater.com · CC BY 4.0 · Source record

This map is one model’s reconstruction of the world, an estimate built from evidence and not a photograph.

Where this word appears on Triassic Water

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Sources

The definition: U.S. National Park Service, “Glossary of Paleontological Terms”, dated August 13, 2024 on the page itself, https://www.nps.gov/subjects/fossils/glossary-of-paleontological-terms.htm, read 23 September 2026. A work of the U.S. Government, in the public domain. Courtesy of the National Park Service.
How this page is made: The definition is quoted exactly. The one plain sentence under the word is ours, and it may not add a number, a date, a place or a living thing the definition does not already name. The picture carries its own credit.