Cambrian explosion

American  

noun

1. the rapid appearance during the Cambrian Period of a large number of multicelled life forms which are the ancestors of almost all modern animal phyla.

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Cambrian Explosion Scientific  

1. The rapid diversification of multicellular animal life that took place around the beginning of the Cambrian Period. It resulted in the appearance of almost all modern animal phyla.

2. See Note at Burgess Shale

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Example Sentences

Then came the Cambrian explosion, known as evolution's "big bang", roughly 540 million years ago.

From Barron's • Jan. 28, 2026

By the beginning of the Cambrian explosion of multicellular organisms about 540 million years ago, the ancestors of today’s ecdysozoans were already alive and varied in form and behavior, suggesting they arose even earlier.

From Science Magazine • Nov. 20, 2024

Think of it as the sequel to the more famous, earlier Cambrian explosion, which saw the rapid origin of many different kinds of animal bodies and groups of living things in the seas.

From Slate • Oct. 21, 2024

Magnesium’s online success also has been spurred in part by a Cambrian explosion of products and formulations, each adapted for a different niche in the wellness ecosystem.

From Los Angeles Times • Mar. 6, 2024

Perhaps some key steps in the development of the genetic code, or the Cambrian explosion, or bipedal stature among our ancestors were initiated by cosmic rays.

From "Cosmos" by Carl Sagan