Metazoa Radiata


Animals with Radial Symmetry

Metazoa ├─Porifera (paraphyletic?) └─Radiata ├─Cnidaria └─Bilateria ├─Deuterostomia └─Protostomia ├─Ecdysozoa └─Lophotrochozoa


Polyorchis pencillatus - Red Eye Medusa
Phylum Cnidaria - Class Hydrozoa - Order Anthomedusae - Family Polyorchidae
image copyright © Keith Clements and Jon Gross Marine Life of the Northeast Pacific

Included here are invertebrates with radial symmetry: all longitudinal planes are equal around central body axis. They are also diploblastic (possessing only two germ layers, an ectoderm and endoderm, but, unlike the Bilateria, no mesoderm. Only two phyla belong here - the Cnidaria and Ctenophora

Radiata after Conway Morris, 1993

──○Radiata ├?─Ctenophora └─○Cnidaria ├─┬─†Trilobozoa │ └─†Anabaritida └─┬─○Hydrozoa │ ├─Hydrozoa │ └─○Chondrophora │ ├─Porpitidae │ └─Velellidae └─┬─┬─†Fasciculida │ └─┬─Tentaculata │ └─Nuda └─┬─┬─┬─Scyphozoa (medusa, jellyfish) │ │ └─○Cubozoa │ │ └─○Cubomedusae │ │ ├─Carybdeidae │ │ └─Chirodropidae │ └─┬─†Conularida │ └─†Carinachitiida └─○?Anthozoa ├─†Xianguangiida ├?─Alcyonaria └─┬─Pennatulacea └─┬─†Echmatocriniida └─Anthozoa


Conway Morris, S., 1993

Fautin, DG & SL Romano 2000)

Hou & Bergström, 1997

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page uploaded 7 April 2002, last modified 2 May 2003
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