The Collaborative International Dictionary
Eozoa
Eozoon \E`o*zo"["o]n\, n.; pl. Eozo["o]ns, L. Eozoa. [NL., fr. Gr. 'hw`s dawn + zw^,on an animal.] (Paleon.) A peculiar structure found in the Arch[ae]an 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.
Wiktionary
eozoa
n. (plural of eozoön English)