Corals
Corals (class Anthozoa) belong to the phylum Cnidaria. Corals are colonies of polyp like animals, living mainly in tropical oceans. By asexual reproduction colonies can grow from one coral cell. Corals build reefs because of the calcareous skeletons. In cooler waters corals also occur, but they do not built reefs there.
The coral phylum can be subdivided in Rugosa, Tabulata and Scleractinia corals. Tabulate corals are always colonies, but Rugose corals are often solitary. All corals have calcareous skeletons.
Rugosa and Tabulata occur in sediment from the Ordovician period until extinction at the end of the Permian period. Scleractine corals developed in the middle Triassic period and at present they are the most important builders of reefs in the world. Their skeleton consists of fast soluble Aragonite. Commonly only prints of these fossils are found. In the fossils you can often perfectly recognize the separate chambers of the coral cells.
Example of a Rugose coral.
 Click here for information where to find these fossils.
 Go to the Photo page to view photographs of Corals. |
