Blakeoceras is a nautiloid cephalopod from the Oncocerida family Nothoceratidae with a curved shell that lived in shallow seas from the Silurian to the Middle Devonian in what has become Europe. The shell of Blakeoceras is moderately curved (cyrtoconic) with the ventral side on the outer curvature (exogastric) Chambers in the phragmocone are short and wide, separated by straight, close spaced septa. Body chamber short. Siphuncle ventro-marginal, with internal, radial actinosiphonate deposits and concave segments.