ECDISOZOO superphylum of the animal kingdom, whose scientific name is ecdysozoa, from the Greek ekdisis, 'removal', and zoo, 'animal', belonging to the protostomes. Although its classification was proposed rather recently (1997), its relevance was initially suggested more than a century ago. It brings together several phyla, of which the most important are arthropods and nematodes (worms), which have in common the possession of an external cuticle and grow by molts.
