The world's oceans are dwelling to a greater variety of mollusk species than to species of almost every other animal team. ) o grupos de especies animales conocidos hasta ahora, al menos 11 tuvieron su origen en esa época específica, es decir, que allí surgieron las primeras y más antiguas especies animales multicelulares, cuyos descendientes

quite a few animal phyla very first show up from the fossil report through the Cambrian explosion, beginning about 539 million yrs in the past, in beds including the Burgess shale.[ninety six] Extant phyla in these rocks incorporate molluscs, brachiopods, onychophorans, tardigrades, arthropods, echinoderms and hemichordates, in conjunction with man