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 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

This 2025 version of Walking with Dinosaurs uses computer animation to follow the lives of the creatures during the Cretaceous period, from their beginning to their end. —Devonne Goode, Parents, 19 June 2025

Its descendants grew increasingly larger and became true tyrannosaurs, the dominant predators in North America in the late Cretaceous period. —Sara Hashemi, Smithsonian Magazine, 13 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