Eozoons

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. [1913 Webster]