Palaeos:		Invertebrates
Metazoa		Radiata

Radiata

Animals with Radial Symmetry

Metazoa
|--Porifera (paraphyletic?)
`--Radiata
   |--Cnidaria
   `--Bilateria
      |--Deuterostomia
      `--Protostomia
         |--Ecdysozoa
         `--Lophotrochozoa

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

<==o RADIATA 
   |?- CTENOPHORA
   `--o CNIDARIA 
      |--+-- †TRILOBOZOA
      |  `-- †ANABARITIDA
      `--+--o HYDROZOA 
         |  |-- HYDROZOA
         |  `--o CHONDROPHORA
         |     |-- Porpitidae
         |     `-- Velellidae
         `--+--+-- †FASCICULIDA
            |  `--+-- TENTACULATA
            |     `-- NUDA
            `--+--+--+-- SCYPHOZOA (medusa, jellyfish)
               |  |  `--o CUBOZOA
               |  |     `--o CUBOMEDUSAE
               |  |        |-- Carybdeidae
               |  |        `-- Chirodropidae
               |  `--+-- †CONULARIDA
               |     `-- †CARINACHITIIDA
               `--o ?ANTHOZOA
                  |-- †XIANGUANGIIDA
                  |?- ALCYONARIA
                  `--+-- PENNATULACEA
                     `--+-- †ECHMATOCRINIIDA
                        `-- ANTHOZOA

References

Conway Morris, S., 1993

Fautin, DG & SL Romano (2000)

Hou & Bergström, 1997