Cambrian

First geological period of the Paleozoic Era

The Cambrian ( KAM-bree-ən, KAYM-) is the first geological period of the Paleozoic Era and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran Period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents were located in the southern hemisphere surrounded by the vast Panthalassa Ocean.

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