Sea daisy

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For the plant, see Melanthera biflora.
Sea daisies
Scientific classification
Kingdom: Animalia
Phylum: Echinodermata
Class: Asteroidea
Order: Peripodida
Baker, Rowe & Clark, 1986
Family: Xyloplacidae
Genus: Xyloplax
Species

X. janetae
X. medusiformis
X. turnerae

Sea daisies (infraclass Concentricycloidea; order Peripoda) make up an unusual group of deep-sea taxa belonging to the phylum Echinodermata, with three species described in the genus Xyloplax.

Distribution[edit]

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[edit]

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

References[edit]