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Groups of corals

rename
wastedshadows's version from 2016-01-24 11:12

Section

Rugose
clearly developed septa, tabulae and dissepiments
septa inserted at 4 points around the corallite = tetracorals
colonial and solitary forms
built of calcite skeletons
L.Ordivician --> Permian = extinct

 

Scleratina
Septa, dissepiments and tabulae present
septa inserted in cycles of 6 = hexacorals
colonial and solitary forms
built of aragonite skeletons
important reef builders
broadly divided into 2 groups
                          1) Hermatypic = reef making. Forms symbiotic relationships with photosynthetic algea
                          2) Ahermatypic = non-reef making
M.Triassic - recent - extant

 

Tabulata
Absent or very weakly developed septa
present, well developed tabulae
only exists as colonial forms
connections between corallites
built from calcite skeletons
unsure if these are actually corals
L.Ordivician - Permian - extinct