resembling or containing chalk.
(initial capital letter)Geology. noting or pertaining to a period of the Mesozoic Era, from 140 million to 65 million years ago, characterized by the greatest development and subsequent extinction of dinosaurs and the advent of flowering plants and modern insects.
(initial capital letter)Geology. the Cretaceous Period or System.
- cre·ta·ceous·ly, adverb
- non·cre·ta·ceous, adjective
- post·cre·ta·ceous, adjective
- su·per·cre·ta·ceous, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use cretaceous in a sentence
The black market trade in fossils stolen from the richest cretaceous fossil locality in the world has prompted a crackdown.Stopping the Million-Dollar Fossil Thieves: Illegal Trade Meets World of Insatiable Research | Scott Bixby | June 11, 2014 | THE DAILY BEAST
This shallow-water phase existed throughout Jurassic and Lower cretaceous times.The Principles of Stratigraphical Geology | J. E. Marr
Marls and limestones with fossils of an Eocene facies overlie the cretaceous rocks on the Gabun.
Other Ornithosaurs, such as Ornithocheirus from the cretaceous rocks, have the neck much more massive.
There are two remarkable modifications of the early dorsal vertebræ in some of the cretaceous Pterodactyles.
cretaceous Ornithosaurs sometimes differ from birds apparently in admitting the quadrato-jugal bone into the orbit.
British Dictionary definitions for cretaceous (1 of 2)
consisting of or resembling chalk
- cretaceously, adverb
British Dictionary definitions for Cretaceous (2 of 2)
of, denoting, or formed in the last period of the Mesozoic era, between the Jurassic and Tertiary periods, lasting 80 million years during which chalk deposits were formed and flowering plants first appeared
the Cretaceous the Cretaceous period or rock system
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for Cretaceous
The third and last period of the Mesozoic Era, from about 144 to 65 million years ago. During this time the supercontinent Pangaea continued to split up, with modern-day South America and Africa splitting apart, the Atlantic Ocean widening, and India disconnecting itself entirely from the other landmasses to which it was attached. Dinosaurs continued to be the dominant terrestrial animals, but many insect groups, modern mammals and birds, and the angiosperms (flowering plants) also first appeared. The Cretaceous Period ended with a mass extinction event in which about 75 percent of all species, including marine, freshwater, and terrestrial organisms, became extinct. See Chart at geologic time.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.