일반명 : 판상산호(Tabulate Corals) 체인산호(Chain Coral)

학명 : Halysites sp.

지질시대 : 고생대 실루리아기(Silurian period)

원산지 : Louisville limestone in Jefferson County, Kentucky, USA

체인산호(Chain Coral)

Halysites (meaning chain coral) is an extinct genus of Silurian tabulate coral

(Order Tabulata) Colonies range from less than one to tens of centimeters in diameter,

and they fed upon plankton.

판상산호(Tabulate Corals)

The tabulate corals, forming the order Tabulata, are an extinct form of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, 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 (septae). 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 Chaetetes, Favosites, Halysites, Heliolites, Pleurodictyum, Sarcinula and Syringopora. Like rugose corals, 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 and Devonian. Sea levels rose in the Devonian, and tabulate corals became much less common.

They finally became extinct in the Permian-Triassic extinction event.