A Collection of Cambrian Fossils

When you're standing in a museum surrounded by fossils, you can almost imagine drifting through time to when long-extinct creatures swam the ocean. Found all over the world, these fossils can be read by scientists like pages from the book of the past. They tell not only an evolutionary story — the family tree of life — but also how these creatures used to live. Fossils can be found throughout the geologic history of earth, going back billions of years. Here we explore one of the most exciting of times, the Cambrian, when many of the major groups of animals familiar to us today first appear as conspicuous fossils. This is often referred to as the Cambrian Explosion.

The basic body plans of all modern animals were set during the Cambrian Period, 542 - 488 million years ago. Your friends, family, and pet turtle may not look much like the creatures here. But we and our fellow animals are heirs of these ancient ocean dwellers. Changes in Earth’s climate and ocean oxygen levels may have fueled rapid diversification during this period. Another possible cause may have been the interactions among the increasingly complex animals. Competition and predation often spark innovation. Not every Cambrian body plan was successful. But those that did succeed set the pattern for every animal that followed—in the water and on land.