Cnidaria Anthozoa


Corals, Sea anemones, Sea Pens, Etc.

Cnidaria ├─Anthozoa │ ├─Octocorallia (Alcyonaria) │ └─Hexacorallia (Zoantharia) │ ├─Actiniaria │ └─┬─Tabulata │ └─┬─Rugosa │ └─Scleractinia └─┬─Hydrozoa └─┬─┬─Scyphozoa │ └─Cubozoa └─Conulata

The Cnidaria  

Body Form
The deadly Nematocysts
Evolutionary history

Cambrian to Recent

Epizoanthus scotinus
Class Anthozoa - Subclass Ceriantipatharia - Order Ceriantharia - Family Zoanthidae
image copyright © Keith Clements and Jon Gross Marine Life of the Northeast Pacific

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.


──○Anthozoa ├─Octocorallia └─○Zoantharia [Hexacorallia] ├─┬─†Kilbuchophyllida │ └─┬?─○Ceriantharia │ └─┬─○Corallimorpharia │ ├─┬?─Ptychodactiidae* [Ptychodactiatria] │ │ └─Actiniaria │ └─┬─†Numidiaphyllida │ └─Scleractinia [Madreporaria] └─┬─†Tabuloconida └─┬─†Cothoniida └─┬─†Tabulata └─┬─†Heliolitida └─┬─┬?─†Heterocorallia │ └─†Rugosa └─┬?─Antipatharia └─Zoanthidea

Cladogram Reference(s):

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


University of California Museum of Paleontology -- Introduction to the Anthozoa

Tree of Life - Anthozoa

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page uploaded 16 June 2002
checked ATW050516
(originally uploaded on Kheper Site 3 June 1999)
page by M. Alan Kazlev (Creative Commons License)
dendrogram by Mikko Haaramo