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Table 1
Generalized Classification of the Phylum Cnidaria
With Known Geologic Ranges


Groups that include stony corals are in bold face type. The names of the most important fossil group are CAPITALIZED. Polyp groups without skeletons are italicized.

Taxonomic Category Geologic Range


Class Hydrozoa Vendian1 to Holocene
Class Scyphozoa Vendian to Holocene
Class Anthozoa Vendian to Holocene
Subclass Octocorallia
Vendian to Holocene
Subclass Zoantharia
Cambrian to Holocene
Group 1
Order Tabulaconida
Lower Cambrian
Order Cothoniida
Middle Cambrian
Order TABULATA
Lower Ordovician to Upper Permian
Order Heliolitida
Middle Ordovician to Middle Devonian
Order RUGOSA
Middle Ordovician to Upper Permian
Order Heterocorallia
Upper Devonian to Middle Carboniferous
Order Zoanthidia
Holocene
Group 2
Order Kilbuchophyllida
Middle Ordovician
Order Numidiaphyllida
Middle Permian
Order SCLERACTINIA
Middle Triassic to Holocene
Order Corallimorpharia
Holocene
Order Actiniaria
Holocene

1 Latest Precambrian period.


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