Corals and Bryozoans

In tropical and subtropical shallow sea deposits fossil corals are very often found. The hard calcareous skeletons of the coral colonies fossilize very well. Corals are colonies of small polyp-like animals. Through asexual division entire colonies are formed from one coral calyx, which can build up entire reefs. Although most corals form colonies, solitary corals also occur. Bryozoans are similar to corals because they also form colonies with a calcareous skeleton. However, the structure is different and they belong to a separate group.