Phylum of small, aquatic, colonial animals, related to the Brachiopoda; many colonies possess a well-developed, calcite skeleton which comprises microscopic, box-like divisions, each housing an individual animal possessing ciliated tentacles and a coelom. Food is collected by the tentacles which surround the mouth and are borne on a ridge called the ‘lophophore’. Reproduction takes place by (a) asexual budding, and (b) the release of larvae which give rise to new colonies. There is a possible bryozoan fossil from the Late Cambrian, and bryozoans have occurred abundantly from the Ordovician to the present day. Branched colonies are common fossils in some rocks. They were important reef builders and binders in the Phanerozoic, and underwent several great radiations. See ectoprocta.