Cheilostomatida

Cheilostomatida Temporal range: Late Jurassic–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Schizoporella with serpulid tubes; Cape Cod Bay, Duck Creek, near Wellfleet, Massachusetts.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Bryozoa
Class:	Gymnolaemata
Order:	Cheilostomatida Busk, 1852
Suborders
Aeteina Belluloporina Cheilostomatida incertae sedis Ascophora Flustrina Inovicellina Malacostegina Membraniporina Scrupariina Tendrina Thalamoporellina
Synonyms
Anasca: synonym of Flustrina Acophora: synonym of Flustrina Ascophorina: synonym of Flustrina Neocheilostomatina: synonym of Flustrina

Cheilostomatida, also called Cheilostomata, is an order of Bryozoa in the class Gymnolaemata.^[1]

They are exclusively marine, colonial invertebrate animals. Cheilostome colonies are composed of calcium carbonate and grow on a variety of surfaces, including rocks, shells, seagrass and kelps. The colony shapes range from simple encrusting sheets to erect branching and even unattached forms. As in other bryozoan groups, each colony is composed of a few to thousands of individual polypides. Each individual has a U-shaped gut, and no respiratory or circulatory system. Unique among bryozoans, cheilostome polypides are housed in a box-shaped zooids, which do not grow larger once the zooid is mature. The opening through which the polypide protrudes is protected by a calcareous or chitinous lidlike structure, an operculum. Cheilostomes possess avicularia, which have modified the operculum into a range of mandibles (possibly for defense) or hair-like setae (possibly for cleaning).

The cheilostomes are the most abundant and varied of modern bryozoans. The classification in suborders is based upon frontal calcification and the mechanism of lophophore protrusion.