[ 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.
Origin of Archaeocyathid
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019