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

The latest study broadens our understanding of ecosystems in the Cretaceous period (roughly 145 to 66 million years ago), according to the researchers. —David Faris, Newsweek, 10 July 2024

Not all experts are convinced this means Cretaceous ants, too, chatted via pheromones. —science.org, 3 July 2024

Skeletons had been found in the area, especially Spinosaurus, from the late Cretaceous period. —Bethany Brookshire, Scientific American, 27 June 2024

Like birds, mammals are another elusive group in the Late Cretaceous fossil record. —Kristi Curry Rogers, Scientific American, 1 Feb. 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