eozoon
E`o*zo"ön, n.; pl. Eozoöns, L. Eozoa. Etym: [NL., fr. Gr. 'hw`s dawn + zw^,on an animal.] (Paleon.) Defn: A peculiar structure found in the Archæan limestones of Canada and other regions. By some geologists it is believed to be a species of gigantic Foraminifera, but others consider it a concretion, without organic structure.