3 min read The Cambrian period, part of the Paleozoic era ... more readily than their soft-bodied precursors. These included brachiopods, which lived in shells resembling those of clams or ...

Internal, genetic factors were also crucial. Recent research suggests that the period prior to the Cambrian explosion saw the gradual evolution of a "genetic tool kit" of genes that govern ...

This is an illustration of marine fossils that have existed since the Cambrian. Represented taxa include brachiopods, trilobites, ammonites, bivalves, and decapods. Disclaimer: AAAS and EurekAlert!

These layers of sedimentary rock were deposited in Cambrian time, when another shallow sea covered this region. Among the fossilized remains found within these layers are brachiopods, trilobites ...

A volcanic eruption occurred during the Cambrian period. The pyroclastic flow and ... The pyroclastic flow even preserved ...