Bourgueticrinida, the sea lilies, has traditionally been viewed as an order of Articulata and a sister taxon to Comatulida.

Late in their development, the larvae are attached to the seabed by a stalk, but this is broken at metamorphosis and the juvenile crinoid is free living.

The body has an endoskeleton made from a number of articulated calcareous plates known as ossicles covered by a thin epidermis.

It is in the shape of a cup (the calyx) with a lid (the tegmen) which has a central mouth and an anus near the edge, the gut being U-shaped.

There is a ring of clawlike appendages (the cirri) near the base of the aboral underside; these grip the substrate to keep the feather star in place.

Here it is formed into a bolus with mucus and moved down to the mouth by the actions of the cilia, being retained in the groove by the lappets.

Many other invertebrates live as commensals among the rays of crinoids and it may be these succulent morsels that are the principal objective of most predators.

[6] The comatulid Florometra serratissima, in the north east Pacific, has been reported as being preyed on by the graceful decorator crab[7] Oregonia gracilis and the sunflower seastar Pycnopodia helianthoides.