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Archaeocyatha
Archaeocyatha An extinct phylum of reef-forming organisms known only from the Cambrian. They were cup-like, usually 10–30 mm in diameter and up to 50 mm high. The cylindrical, conical, or discoid cup often had an irregular outline or outgrowths. The outer wall had simple pores or was partially displaced by dissepiments. The inner wall usually had one longitudinal row of pores between intercepts. The intervallum contains dissepients, rods, and bars or septa. Some were solitary, others colonial. In some respects they were similar to both sponges and corals, and may represent a true advance in evolutionary grade over the former. It is possible that they lived in a symbiotic relationship with some trilobites. The cause of their extinction is not known.
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MICHAEL ALLABY. "Archaeocyatha." A Dictionary of Zoology. 1999. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Archaeocyatha." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1O8-Archaeocyatha.html MICHAEL ALLABY. "Archaeocyatha." A Dictionary of Zoology. 1999. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-Archaeocyatha.html |
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Archaeocyatha
Archaeocyatha Extinct phylum of reef-forming organisms known only from the Cambrian. They were cup-like, usually 10–30 mm in diameter and up to 50 mm in height. In some respects they were similar to both sponges and corals, and may represent a true advance in evolutionary grade over the former. It is possible that they lived in a symbiotic relationship with some trilobites. The cause of their extinction is not known. There were two classes: Regulares and Irregulares.
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Cite this article
AILSA ALLABY and MICHAEL ALLABY. "Archaeocyatha." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "Archaeocyatha." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1O13-Archaeocyatha.html AILSA ALLABY and MICHAEL ALLABY. "Archaeocyatha." A Dictionary of Earth Sciences. 1999. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-Archaeocyatha.html |
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