Topic summary
Crinoidea
Extracted from the Wikipedia article Crinoid.
Taxonomy
Crinoidea has been accepted as a distinct clade of echinoderms since the definition of the group by Miller in 1821. It includes many extinct orders as well as four closely related living orders (Comatulida, Cyrtocrinida, Hyocrinida, and Isocrinida), which are part of the subgroup Articulata. Living articulates comprise around 540 species.