Cambrian Period
541-485 million years ago
About this Period
Explosion of complex life forms
Detailed Overview
The Cambrian period marked a profound change in life on Earth known as the "Cambrian Explosion." During this time, nearly all modern phyla of animals appeared in the fossil record. Complex organisms evolved mineralized shells, exoskeletons, and other hard parts, dramatically improving their preservation as fossils. The period saw the emergence of the first arthropods, chordates, and a variety of other animal forms. Notable creatures included trilobites, Anomalocaris, and the first vertebrates.
