Higher classification Xyloplacidae Rank Genus | Scientific name Xyloplax | |
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Infraclass ConcentricycloideaBaker, Rowe & Clark, 1986 Order PeripodidaBaker, Rowe & Clark, 1986 Family XyloplacidaeBaker, Rowe & Clark, 1986 Similar Pyura spinifera, Homalozoa, Brittle star, Velatida, Asterozoa | ||
Sea daisy nature diary 117
Sea daisies (infraclass Concentricycloidea; order Peripodida) make up an unusual group of deep-sea taxa belonging to the phylum Echinodermata, with three species described in the genus Xyloplax.
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Distribution
Sea daisies have been discovered in three localities, including deep-sea habitats off New Zealand, the Bahamas and most recently from the northern central Pacific. They have been collected primarily from sunken, deep-sea (1000+ meters) wood. Although known from only a handful of specimens initially, nearly 100 specimens have been collected from the Bahamas with decent numbers collected from the north central Atlantic.
Classification
Since they were discovered in 1986, their position within the echinoderms has been debated. At first they were placed in a new class, Concentricycloidea, since it was unclear whether they might have affinities with asteroids or ophiuroids. The former view gained acceptance, and since 2006, they are currently considered a sister group to the Infraclass Neoasteroidea, which represents all post-Paleozoic asteroids within the Class Asteroidea.
Class Asteroidea, Infraclass Concentricycloidea, Order Peripoda (or Peripodida), Family Xyloplacidae
