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• Cambrian explosion
  Cambrian explosion

  noun

  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.
• Cambrian Explosion
  Cambrian Explosion

  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.

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

See Examples For:

Cambrian explosion Cambrian Explosion

The Ediacaran period occurred before the Cambrian explosion, a major evolutionary turning point when rising oxygen levels helped complex organisms diversify rapidly across Earth's oceans.

From Science Daily ● May 12, 2026

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

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

It shows that important elements of their body plan were already established shortly after the Cambrian Explosion, a time when life was rapidly diversifying.

From Science Daily ● Apr. 3, 2026

It's not always an absolutely gobsmacking profusion of uncontrollably bizarre life, as occurred with what's aptly called the Cambrian Explosion, a period about 540 million years ago when evolution got extremely creative.

From Salon ● Feb. 25, 2025

During the Cambrian Explosion more than 500 million years ago, these weird worms — which lived inside long, cone-shaped tubes — were some of the most common predators on the seafloor.

From New York Times ● Mar. 26, 2024

Between 540 million and 485 million years ago, during the Cambrian period, so many new, complex animal life forms arose that paleontologists speak of the Cambrian Explosion or the Biological Big Bang.

From Science Magazine ● May 1, 2023

Paleontologists refer to this event as the Cambrian Explosion, named after the first period in the Paleozoic.

From Textbooks ● Jan. 1, 2017