Tabulata, commonly known as tabulate corals, are an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

forms of coral. They are almost always

colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 a ...

, forming colonies of individual hexagonal cells known as

corallite A corallite is the skeletal cup, formed by an individual stony coral polyp, in which the polyp sits and into which it can retract. The cup is composed of aragonite, a crystalline form of calcium carbonate, and is secreted by the polyp. Corallit ...

s defined by a

skeleton A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

, similar in appearance to a honeycomb. Adjacent cells are joined by small pores. Their distinguishing feature is their well-developed horizontal internal partitions (''tabulae'') within each cell, but reduced or absent vertical internal partitions ( ''septa''). They are usually smaller than rugose corals, but vary considerably in shape, from flat to conical to spherical. Around 300 species have been described. Among the most common tabulate corals in the fossil record are ''

Aulopora ''Aulopora'' is an extinct genus of tabulate coral Tabulata, commonly known as tabulate corals, are an order of extinct forms of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defi ...

'', ''

Favosites ''Favosites'' is an extinct genus of tabulate coral characterized by polygonal closely packed corallites (giving it the common name "honeycomb coral"). The walls between corallites are pierced by pores known as mural pores which allowed transfer ...

'', ''

Halysites ''Halysites'' (meaning ''chain coral'') is an extinct genus of tabulate coral. Colonies range from less than one to tens of centimeters in diameter, and they fed upon plankton. These tabulate corals lived from the Ordovician to the Devonian (fro ...

'', ''

Heliolites ''Heliolites'' is a large and heterogenous genus of extinct tabulate corals in the family Heliolitidae. Specimens have been found in Ordovician to Devonian beds in North America, Europe, Africa, Asia, and Australia. The genus is particularly abu ...

'', ''

Pleurodictyum ''Pleurodictyum'' is an extinct genus of tabulate corals, characterized by polygonal corallites. Colonies commonly encrust hard substrates such as rocks, shells and carbonate hardgrounds. Distribution Fossils of ''Pleurodictyum'' have been fou ...

'', ''Sarcinula'' and ''

Syringopora ''Syringopora'' is an extinct genus of phaceloid tabulate coral. It has been found in rocks ranging in age from the Ordovician to the Permian, although it was most widespread during the Silurian, Devonian, and Carboniferous periods. Among other p ...

''. Tabulate corals with massive skeletons often contain endobiotic symbionts, such as cornulitids and ''

Chaetosalpinx ''Chaetosalpinx'' is an ichnogenus of bioclaustrations (a type of trace fossil). ''Chaetosalpinx'' includes straight to sinuous cavities that are parallel to the host's axis of growth. The cavity is circular to oval in cross-section and it lacks ...

''. Like

rugose corals The rugosa, also called the tetracorallia or horn coral, are an extinct order of solitary and colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., '' Caninia'', '' Lophophyllidium'', '' Neoza ...

, they lived entirely during the Paleozoic, being found from the Ordovician to the Permian. With Stromatoporoidea and rugose corals, the tabulate corals are characteristic of the shallow waters of the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

and

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

. Sea levels rose in the Devonian, and tabulate corals became much less common. They finally became extinct in the Permian–Triassic extinction event.

Gallery

Image:HalysitesSilurian.jpg, ''Halysites'' sp. from the

of Ohio. View of colony surface. Image:Tabulate_coral_etched_section.jpg, Etched section of an Ordovician tabulate coral Image:AuloporaDevonianSilicaShale.jpg, ''Aulopora'' from the Silica Shale (Middle

) of northwestern Ohio. Image shows colony origin encrusting a brachiopod. Image:Rafinesquina ponderosa (Hall) ventral.JPG, The coral ''Protaraea richmondensis'' on the brachiopod ''Rafinesquina ponderosa'';

Whitewater Formation The Whitewater Formation is a geologic formation in Ohio and Indiana. It preserves fossils dating back to the Ordovician period.Waynesville Formation The Waynesville Formation is a geologic formation in Ohio and Indiana. It preserves fossils from the Late Ordovician period. See also * List of fossiliferous stratigraphic units in Ohio * List of fossiliferous stratigraphic units in Indiana ...

, Upper Ordovician, Caesar Creek, Ohio.

References

* Invertebrate Fossils; Moore, Lalicker, & Fischer; McGraw-Hill 1952. * Treatise on Invertebrate Paleontology Part F, Coelenterata. Geological Society of America and Univ Kansas Press. R.C. Moore (ed). Hexacorallia Prehistoric animal orders Cnidarian orders {{permian-animal-stub