Rare- Caligula AV quinarius- Joe Geranio photo collection.

Caligula AV quinarius dated to COS IIII of his principate are extremely rare. This is in my Joe Geranio photo collection.  In my opinion after Augustus stopped the quaternion AV aureus which was 30mm or greater, this smaller form of donative was used from Julio Claudian times (including Augustus) into Nervan times.  My opinion. Joe Geranio- Julio Claudian Iconographic Association.