Source : Webster's Revised Unabridged Dictionary (1913)

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.