Cambrian

American  

[kam-bree-uhn] / ˈkæm bri ən /

adjective

1. Geology. noting or pertaining to a period of the Paleozoic Era, occurring from 570 million to 500 million years ago, when algae and marine invertebrates were the predominant form of life.

2. of or relating to Cambria; Welsh.

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noun

1. Geology. the Cambrian Period or System.

2. a native of Cambria; Welshman.

Cambrian British  

/ ˈkæmbrɪən /

adjective

1. of, denoting, or formed in the first 65 million years of the Palaeozoic era, during which marine invertebrates, esp trilobites, flourished

2. of or relating to Wales

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noun

1. the Cambrian period or rock system

2. a Welsh person

Cambrian Scientific  

/ kăm′brē-ən,kām′- /

1. The first period of the Paleozoic Era, from about 540 to 505 million years ago. During this time warm seas and desert land areas were widespread, and animal life diversified rapidly during what is known as the Cambrian Explosion.

2. See Chart at geologic time

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Other Word Forms

• post-Cambrian adjective

Etymology

Origin of Cambrian

1580–90; < Medieval Latin Cambri ( a ) Wales, Latinization of MWelsh Cymry Wales, literally Welshmen ( see Cymry) + -an

Example Sentences

Previous genetic studies and fossil traces suggested that many animal lineages existed before the Cambrian explosion.

From Science Daily • Apr. 6, 2026

The discovery shows that many major animal groups were already present before the Cambrian Period began.

From Science Daily • Apr. 6, 2026

The fossil was collected from the middle Cambrian Wheeler Formation in Utah's House Range.

From Science Daily • Apr. 3, 2026

Hidden among the clouds that cling to the Cambrian mountains, Graham has brought me to a secret location, armed with a home-made rake.

From BBC • Mar. 8, 2026

Soon after the Cambrian explosion, the oceans teemed with many different forms of life.

From "Cosmos" by Carl Sagan