Cheilostomata

Cheilostomata Temporal range: Late Jurassic–Recent PreЄ Є O S D C P T J K Pg N
Eurystomella bilabiata
Scientific classification
Kingdom:	Animalia
Phylum:	Bryozoa
Class:	Gymnolaemata
Order:	Cheilostomata Busk, 1852
Suborders
Ascophora Flustrina Inovicellina Malacostegina Scrupariina

Cheilostomata, an order of Bryozoa in the class Gymnolaemata, 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, which has a U-shaped gut, and no respiratory, circulatory, or nerve 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 of 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.

Evolution

Cheilostomes first appeared in the Late Jurassic (Pyriporopsis) but diversified very slowly during the Early Cretaceous, with only 1 family known up to the Albian. During the Late Cretaceous, cheilostomes diversified rapidly to reach a level of more than 20 families in the Maastrichtian. This diversification is thought to be a consequence of the evolution of a new larval type.^[1] Though the K-T Extinction Event had some impact on genetic diversity, the rapid diversification continued into the Eocene, then apparently reaching a plateau of about 50 families up to the Recent.

References

1. ^ Taylor, P.D., 1988. Major radiations of cheilostome bryozoans: triggered by the evolution of a new larval type? Historical Biology 1: 45-64

This bryozoan-related article is a stub. You can help Wikipedia by expanding it.v · Categories: Bryozoans Invertebrate stubs Wikimedia Foundation. 2010. Игры ⚽ Нужен реферат? Gymnolaemata Control Yuan Look at other dictionaries: Cheilostomata — Cheilostomata …   Wikipédia en Français Cheilostomata — ▪ bryozoan order       major group of calcified bryozoans (small, colonial, aquatic invertebrate animals) that first appeared during the Jurassic period (200 to 146 million years ago). Individual members of the cheilostome colony are small… …   Universalium cheilostomata — chei·lo·sto·ma·ta …   English syllables cheilostomata — ˌkīləˈstōməd.ə noun plural Usage: capitalized Etymology: New Latin, from chil + stomata : a large order of bryozoans (class Gymnolaemata) having the colony erect or encrusting, the zooecia more or less tubular, and the aperture closed by a… …   Useful english dictionary Bryozoa — Temporal range: Upper Cambrian–Recent[1] …   Wikipedia moss animal — bryozoan. [1880 85] * * * ▪ invertebrate Introduction also called  bryozoan,         any member of the phylum Bryozoa (also called Polyzoa or Ectoprocta), in which there are about 5,000 extant species. Another 15,000 species are known only from… …   Universalium Gymnolaemata — Reteporella grimaldii Systematik Abteilung: Gewebetiere (Eumetazoa) Unterabteilung: Bilateria ohne Rang …   Deutsch Wikipedia Ascophora — Taxobox name = Ascophora fossil range = Late Cretaceous Recent regnum = Animalia phylum = Bryozoa classis = Gymnolaemata ordo = Cheilostomata subordo = Ascophora subordo authority = Levinsen, 1909 subdivision ranks = Infraorders subdivision =… …   Wikipedia Operculum (bryozoa) — In the bryozoan order Cheilostomata, the operculum is a calcareous or chitinous lid like structure that protects the opening through which the polypide protrudes. Many species have modified the operculum in specialized zooids (avicularia) to form …   Wikipedia Malacostegina — Temporal range: Late Jurassic–Recent …   Wikipedia 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”