Palaeos:		Cnidaria
Cnidaria		Anthozoa

Anthozoa

Corals, Sea anemones, Sea Pens, Etc.

CNIDARIA  
|--Anthozoa
|  |--Octocorallia (Alcyonaria)
|  `--Hexacorallia (Zoantharia)
|     |--Actiniaria
|     `--+--Tabulata
|        `--+--Rugosa
|           `--Scleractinia
`--+--Hydrozoa
   `--+--+--Scyphozoa
      |  `--Cubozoa
      `--Conulata

Anthozoans include corals, sea anemones, sea pens, and related organisms. These animals are either solitary or colonial polyps that live attached to a substrate (surface). This is the largest and ecologically the most important group of cnidarians.  Anthozoans are unique in their absence of a medusiod phase and polyps much larger than are found in the other two classes. The polyp shows biradial symmetry, with the body cavity divided by septa   There are 6,000 known recent species.

Phylogeny

<==o ANTHOZOA 
   |-- OCTOCORALLIA
   `--o ZOANTHARIA [Hexacorallia]
      |--+-- †KILBUCHOPHYLLIDA
      |  `--+?-o CERIANTHARIA
      |     `--+--o CORALLIMORPHARIA
      |        |--+?- Ptychodactiidae* [Ptychodactiatria]
      |        |  `-- ACTINIARIA (merivuokot)
      |        `--+-- †NUMIDIAPHYLLIDA
      |           `-- SCLERACTINIA [Madreporaria]
      `--+-- †TABULOCONIDA
         `--+-- †COTHONIIDA
            `--+-- †TABULATA
               `--+-- †HELIOLITIDA
                  `--+--+?- †HETEROCORALLIA
                     |  `-- †RUGOSA
                     `--+?- ANTIPATHARIA
                        `-- ZOANTHIDEA

Conway Morris, S., 1993: The fossil record and early evolution of the Metazoa. --Nature, vol. 361, 21 January, pp. 219-225

--iNet: The Tree of Life

Fautin, D. G., Romano, S. L. & Oliver, W. A. Jr., 1999: Zoantharia - Sea Anemones and corals. --iNet: The Tree of Life

Parker, S. P. (ed.), 1982: Synopsis and classification of living organisms. Vols. 1 & 2 --McGrew-Hill Book Company

Links

Introduction to the Anthozoa

Tree of Life - Anthozoa