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 eggs are believed to date back 72 million years ago to the Late Cretaceous period, when the region was part of the Ibero-Armorican Island, a prehistoric landmass made up of modern-day Spain, Portugal and southern France. — Toria Sheffield, PEOPLE, 23 May 2026

The animals lived during the Early Cretaceous period between 100 and 120 million years ago. — Michelle Del Rey, USA Today, 15 May 2026

Larger sauropods have been found from later on in the Cretaceous period — one as heavy as 70 tons. — James Doubek, NPR, 14 May 2026

Stretching up to 62 feet long, the ancient predator dwarfed modern giant squid and may have rivaled some of the most formidable hunters of the Cretaceous oceans. — Ryan Brennan, Charlotte Observer, 24 Apr. 2026

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