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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. 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 ² British  

/ krɪˈteɪʃəs /

adjective

1. consisting of or resembling chalk

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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

It is believed, however, that the depth of the cretaceous sea over the island was probably never very great.

From The History of Cuba, vol. 1 by Willis Fletcher Johnson

And from the gigantic lizards of the cretaceous period we find in the overlying tertiary beds the infinite variety of four-legged animals which people our continents to-day.

From Twentieth Century Socialism What It Is Not; What It Is: How It May Come by Edmond Kelly

During the Cretaceous Thermal Maximum, approximately 94 million years ago, global temperatures climbed as much as 14°C above modern levels.

From Science Daily ● Oct. 30, 2026

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

Molecular clock studies have supported the possibility that placental mammals originated well before the end of the Cretaceous.

From Science Daily ● Sep. 28, 2026

“They lived from the late Triassic to the Cretaceous period, though technically they’re not dinosaurs,” Kavita says in a know-it-all sort of way.

From "Dragons in a Bag" by Zetta Elliott

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