Cretaceous

adjective

Cre·​ta·​ceous kri-ˈtā-shəs 

: 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

This site, which falls part of a rich sedimentary layer from the Early Cretaceous period, has long been a hotspot for dinosaur fossils. —Scott Travers, Forbes, 7 Jan. 2025

Theropods, according to the researchers, are rare in the Cretaceous sediments of southern England, making the Bexhill-at-Sea dinosaurs noteworthy. —Jack Knudson, Discover Magazine, 1 Jan. 2025

The scientists therefore conclude that the meteorite impact was the ultimate cause of the mass extinction event at the end of the Cretaceous period. —David Bressan, Forbes, 23 Dec. 2024

Detailed in the Proceedings of the National Academy of Sciences, the Cretaceous trackway was made by a two-toed dinosaur like Microraptor. —Riley Black, Smithsonian Magazine, 16 Dec. 2024

Word History

Etymology

Latin cretaceus resembling chalk, from creta chalk

First Known Use

1832, in the meaning defined above

Kids Definition

Cretaceous

adjective

Cre·​ta·​ceous kri-ˈtā-shəs 

: 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