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Holothuroidea
Holothuroidea (sea cucumbers; phylum Echinodermata, subphylum Echinozoa) A class of worm-like echinoderms which may be free-living or attached. The mouth, surrounded by variably branched tentacles, is at one end of the elongate body, the anus at the other. The calcitic skeleton is not rigid, being reduced to small sclerites (or spicules) of very variable shape: hooks, anchors, rings, and plates. Fossil spicules of sea cucumbers are first encountered in rocks of Ordovician age.
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Cite this article
MICHAEL ALLABY. "Holothuroidea." A Dictionary of Zoology. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Holothuroidea." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O8-Holothuroidea.html MICHAEL ALLABY. "Holothuroidea." A Dictionary of Zoology. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-Holothuroidea.html |
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Holothuroidea
Holothuroidea (holothuroids; sea cucumbers; subphylum Echinozoa) Class of worm-like echinoderms which may be free-living or attached. The mouth, surrounded by variably branched tentacles, is at one end of the elongate body, the anus at the other. The calcitic skeleton is not rigid, being reduced to small sclerites (or spicules) of very variable shape: hooks, anchors, rings, and plates. Fossil spicules of sea cucumbers are first encountered in rocks of Ordovician age.
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Cite this article
AILSA ALLABY and MICHAEL ALLABY. "Holothuroidea." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "Holothuroidea." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O13-Holothuroidea.html AILSA ALLABY and MICHAEL ALLABY. "Holothuroidea." A Dictionary of Earth Sciences. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-Holothuroidea.html |
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