See text The Armenoceratidae are a family of early Paleozoic nautiloid cephalopods belonging to the order Actinocerida.

Selkirkoceras is a large armenocerid from the Upper Ordovician with a blunt, flattened, somewhat breviconic shell.

Among the Silurian genera, Elrodoceras has a large shell with the apical part slightly curved, otherwise is straight, and a siphuncle that is narrower than in Armenoceras.

Monocyrtoceras has a siphuncle like that of Elrodoceras, but the entire shell is gently and evenly curved.

Megadiscosorus is similar to Armenoceras, but more breviconic and slightly exogastrically cyrtoconic and with the siphuncle in contact with the ventral wall.