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[ahr-kee-oh-sahy-uh-thid, ahr-kee-uh-] /ˌɑr ki oʊˈsaɪ ə θɪd, ɑrˌki ə-/
one of the marine invertebrates of the extinct phylum Archaeocyatha, widely distributed during the Cambrian Period, having a limy, typically conical or cylindrical skeleton composed of sievelike inner and outer walls.
< New Latin Archaeocyath(us) genus name (archaeo- archaeo- + Latin cyathus ladle < Greek kýathos) + -id2 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Encyclopedia Article for Archaeocyathid


any member of an extinct group of marine organisms of uncertain relationships found as fossils in marine limestones of Late Precambrian and Early Cambrian age (Precambrian time ended about 542 million years ago and was followed by the Cambrian). The archaeocyathid fossils represent the calcareous supporting structure built by a creature of which little is known. Indeed, it has been considered possible that the archaeocyathid organism was some sort of calcareous algae, although this seems unlikely.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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