corals

Coral consist of two layers, an outer endoderm and an inner endoderm. corals have an calcium carbonate skeleton, which is of imense importance in the geological record.

Tabula- horizontal plates dividing the coralite skeleton

calice-Bowl shaped depression where the soft polyp sits

columella- Axial rods which supports the septa, running up the centre of some corals

septa- vertical plates, dividing the corallite skeleton

dissepiments- curved plates connected to septa and tabulae


Rusgose Corals 

• These extinct corals are either solitary or colonial. the epitheca, or outer layer, is often wrinkled and may be hornshaped.
• the have 1 plane of symmetry known as bilateral symmetry
• they have a columella
• may have dissepiments but not always present
• usually large

Tabulate Corals

• These are extinct
• always colonial
• usually small
• they show radial symmetry
• no speta or undeveloped
• may have dissepiments
• dont have a columella

Scleratinian corals 

• either solitary or colonial
• usually small
• radial symmetry hexagonal
• show 6 primary septa
• may have disspeiments
• always have tabulae