cambrian explosion or cambrian radiation event that was characterized by the appearance of many of the major phyla

animal animals anomalocaridids anomalocaris appearance aquatic background biology briggsi cambrian canadensis carnivorous characterized creature dinomischus early epoch era event evolution explosion extinct fauna form fossil hallucigenia illustration life major make many marine milion modern multicellular nature ocean opabinia organism paleoart paleontology paleozoic period phyla pirania predator prehistoric primeval primitive radiation scene science sea seascape swimming that underwater vertebrate was water wildlife