\------v------/ | | | | | | \------v------------/ | | | Angustistellæ | +Desmosticha+ | +Autechinida+ | | | | Colocrinæ | | | | | Sphæronitidæ | Phytastra | | | | | | | | | | | Eocidaridæ | | Eleutherocrina | | | | | | | | | | | | Ophiastra | | Agelacrinæ | | +Discogastra+ | | +Cystidea+ | | | | | | | | | | | | | | | | Melonitida | Phatnocrinæ | Brisingastra | Palechinida | +Brahiata+ Pentremitida | | +Echinida+ | | +Blastoidea+ | | | | | | | | | | | | Colastra \----------v-----------------/ \-------v-----------/ | | +Brachiata+ | | Crinoida | | Crinastra | | | \-------------------------v----------------------------------/ | Tocastra +Actinogastra+ +Asterida+ | Phracthelminthes | Cœlomati | Gastræa