The Paleozoic, or "Old Life", Era is sometimes called the "Age of Fishes." It began with the Cambrian Explosion, a short period of time in which an enormous diversification of complex life occurred, and ended with the great Permian/Triassic mass extinction. It is composed of the Cambrian, Ordovician, Silurian, Devonian, Carboniferous (Mississippian and Pennsylvanian in North America), and Permian Periods. This category is for any website dealing with the Paleozoic fossil record.
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