Explain the classification of phylum echinodermata of non chordates?

The phylum echinodermata is divided into many classes. It includes asteroidea, ophiuroidea, echinoidea, holothuroidea and crinoidea. The asteroidea are also known as the star form organisms. There body is flat and have short spines. Their arms are marked with the absence of pedicellariae. The oral surface includes mouth and ambulacral grooves while the aboral surface has anus. The ophiuroidea are also known as snake tail form organisms. There body is flat and have short spines. Their arms are marked with the absence of pedicellariae. The oral surface includes mouth and there are no ambulacral grooves with the absence of anus. The echinoidea are hedgehog form organisms. Their body is disc like with absence of arms and ambulacral grooves. The oral surface includes mouth while the aboral surface has anus and madreporite. The teeth have biting and chewing apparatus known as Aristotle’s lantern. The spines vary in their size. The pedicellariae are present. The holothuroidea are known as sea cucumber form organisms. The body is cylindrical with absence of arms and ambulacral grooves. The oral surface includes mouth and tentacles while the aboral surface has anus and madreporite which is internal. The pedicellariae and spines are absent. The crinoidea are known as the lily form organisms. Their body has a disc which helps in the attachment to substratum. The pedicellariae and spines are absent. Their arms are branched and have ambulacral grooves. They are also known as sea lilies. The oral surface includes the mouth and anus. There is no madreporite.