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 dinosaur lived in the late Cretaceous period, around 67.5 million years ago, AP reported. —Ashley J. Dimella, FOXNews.com, 11 July 2025

While massive dinosaurs stomped around during the Triassic, Jurassic and Cretaceous periods, these little creatures were skittering around under their feet. —Sarah Kuta, Smithsonian Magazine, 11 July 2025

The ancient Romans On Morocco’s Mogador Island, archaeologists found Early Cretaceous fossils mixed with Roman artifacts, despite the island’s young geological age. —Real-Time News Team, Miami Herald, 27 June 2025

These clues suggest that fire was a constant presence during the Cretaceous period, fueled by an oxygen-rich atmosphere and intense volcanic activity. —Discover Magazine, 27 June 2025

Word History

Etymology

Latin cretaceus resembling chalk, from creta chalk

First Known Use

1832, in the meaning defined above

Rhymes for Cretaceous

• arenaceous
• argillaceous
• carbonaceous
• contumacious
• coriaceous
• efficacious
• farinaceous
• foliaceous
• membranaceous
• ochraceous
• olivaceous
• ostentatious

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