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• cretaceous
  cretaceous

  adjective

  resembling or containing chalk.
• Cretaceous
  Cretaceous

  adjective

  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

cretaceous

American  

[kri-tay-shuhs] / krɪˈteɪ ʃəs /

adjective

1. resembling or containing chalk.

2. (initial capital letter) 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.

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noun

1. (initial capital letter) the Cretaceous Period or System.

cretaceous ¹ British  

/ krɪˈteɪʃəs /

adjective

1. consisting of or resembling chalk

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Cretaceous ² British  

/ krɪˈteɪʃəs /

adjective

1. 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

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noun

1. the Cretaceous period or rock system

Cretaceous Scientific  

/ krĭ-tā′shəs /

1. 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.

2. See Chart at geologic time

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Other Word Forms

• noncretaceous
  adjective
• postcretaceous
  adjective
• supercretaceous
  adjective
• cretaceously
  adverb

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Etymology

Origin of cretaceous

1665–70; < Latin crētāceus, equivalent to crēt ( a ) chalk, clay ( cf. crayon) + -āceus -aceous; the geological period was defined from the chalk beds of SE England and associated formations

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Example Sentences

See Examples For:

cretaceous Cretaceous

Earliest known mammalian stapes from an early cretaceous eutriconodontan mammal and implications for evolution of mammalian middle ear.

From Nature ● Nov. 12, 2017

Five miles below sea level, and beneath a shifting layer of cretaceous salt deposits, the discoveries have been estimated at 50 billion to 100 billion barrels.

From BusinessWeek ● May 10, 2012

Princeton paleontologists under the leadership of Dr. Glenn L. Jepsen. digging in a cretaceous formation near Red Lodge in southern Montana, found some old broken eggs.

From Time Magazine Archive

And when they nearly disappeared with the cretaceous period, there was created another race with carnivorous propensities and organs, called trachelipods; and those continue still to swarm in the ocean.

From The Religion of Geology and Its Connected Sciences by Edward Hitchcock

They are formed chiefly of crystalline gneissic and granitic rocks and some metamorphic schists and quarzite, with cretaceous and tertiary rocks of varying thickness along its southern edge.

From A Study of Recent Earthquakes by Charles Davison

The Late Cretaceous carnivore is expected to fetch up to $9m when it goes under the hammer on Tuesday.

From BBC ● Oct. 27, 2026

Invictibellatrix, meaning "unconquered female warrior", is one of the smallest and earliest of the group to be found, living in the Early Cretaceous period about 120 million years ago.

From BBC ● Oct. 14, 2026

The finding also suggests that Cretaceous mammals may not have been as anatomically varied as scientists might have inferred from their teeth alone.

From Science Daily ● Sep. 28, 2026

Their teeth were unusually specialized for eating plants compared with the sharper teeth used for eating insects that are common among many Cretaceous mammals.

From Science Daily ● Sep. 28, 2026

I didn't want a little brown aragonite figurine of T. rex, with its mouth open and its teeth bared, nor did I want the Dinosaurs of the Cretaceous Period poster.

From "It All Comes Down to This" by Karen English

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