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
Word origin
[‹ NL Archaeocyath(us) genus name (archaeo-archaeo- + L cyathus ladle ‹ Gk kýathos) + -id2]