Cretaceous

adjective

Cre·​ta·​ceous kri-ˈtā-shəs How to pronounce Cretaceous (audio)
: of, relating to, or being the last period of the Mesozoic era characterized by continued dominance of reptiles, emergent dominance of angiosperms, diversification of mammals, and the extinction of many types of organisms at the close of the period
also : of, relating to, or being the corresponding system of rocks see Geologic Time Table
Cretaceous noun

Examples of Cretaceous in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Early Cretaceous deep-water bedforms west of the Guinea Plateau revise the opening history of the Equatorial Atlantic Gateway. Soo Kim, MSNBC Newsweek, 8 May 2025 Before that period, during the Late Jurassic and Early Cretaceous, fierce aquatic reptilian predators prowled the oceans, including pliosaurids with jaws over six feet long, toothy thalattosuchia crocodyliforms, and fast, fish-like ichthyosaurians. Paul Smaglik, Discover Magazine, 2 May 2025 The gigantic mosasaur lived at the end of the Cretaceous period, around 66 million years ago. Sarah Kuta, Smithsonian Magazine, 29 Apr. 2025 Seeing a hell ant preserved in limestone so far away from Burma indicates that these ants were widely distributed and likely crossed Cretaceous landmasses several times. Laura Baisas, Popular Science, 24 Apr. 2025 See All Example Sentences for Cretaceous

Word History

Etymology

Latin cretaceus resembling chalk, from creta chalk

First Known Use

1832, in the meaning defined above

Time Traveler
The first known use of Cretaceous was in 1832

Browse Nearby Words

Cite this Entry

“Cretaceous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Cretaceous. Accessed 23 May. 2025.

Kids Definition

Cretaceous

adjective
Cre·​ta·​ceous kri-ˈtā-shəs How to pronounce Cretaceous (audio)
: of, relating to, or being the last period of the Mesozoic era of geological history marked by the extinction of the dinosaurs at the close of the period
also : relating to the corresponding system of rocks see geologic time
Cretaceous noun
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!