sea lilies
by:kemonte hall
sea lilies picture
sea lily, stalked echinoderm of the class Crinoidea. Sea lilies are ancient, having reached their peak in the Middle Mississippian period; about 5,000 fossil species are known. About 80 modern species remain. Marine animals, like all echinoderms, they are largely restricted to fairly deep water, from about 35 to 1,000 fathoms (60–300 m). Small organisms and particles are trapped in mucus in the water-vascular (ambulacral) grooves located on the feathery, branching arms and are conveyed to the mouth. Unlike the free-swimming feather stars to which they are related, sea lilies remain permanently attached to the ocean bottom. Two genera, Rhizocrinus andCenocrinus, occur at moderate depths in the Atlantic and Caribbean. Sea lilies are classified in the phylum Echinodermata, class Crinoidea.
Sea lilies occur chiefly in deep waters, where they feed on detritus. Of 80 living species— none more than 60 cm (24 inches) tall—many belong to the genus Metacrinus, distributed from Japan to Australia. A common West Indies species is Neocrinus decorus. More than 5,000 extinct species—some 20 m (65 feet) long—are known. They are important index fossils of the Paleozoic Era (from 542 million to 251 million years ago).
Sea lily, any crinoid marine invertebrate animal (class Crinoidea, phylum Echinodermata) in which the adult is fixed to the sea bottom by a stalk. Other crinoids (such as feather stars) resemble sea lilies; however, they lack a stalk and can move from place to place. The sea lily stalk is surmounted by a bulbous body with frondlike tentacles, and the animal resembles a plant. The stem consists of limy disks, and the body has an internal skeleton of close-fitting limy plates.
Feather Stars and Sea Lilies
The Holopus | Crinoids, or “sea lilies”