Cambrian explosion

Period of major evolutionary diversification of animal life

The Cambrian explosion (also known as the Cambrian radiation or Cambrian diversification) is an interval of time beginning approximately 538.8 million years ago in the Cambrian period of the early Paleozoic, during which a sudden radiation of complex life occurred. The fossil record of this period contains the first appearances of practically every animal phyla, implying that nearly all animal life has its origin during this radiation. It lasted between 13 and 25 million years and resulted in the divergence of most modern metazoan phyla.

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