With the possible addition of an Early Cretaceous orthocerid from the western Caucasus [2] the range of this group increases dramatically to some 350 million years, thus making it one of the longest lived families of the Nautiloidea.

Shells of geisonoceratids are orthoconic or cyrtoconic, that is long and either straight or curved, with a subcircular cross section.

The siphuncle, which varies in position from central to subventral, is composed of generally short, straight to slightly curved, orthochoanitic to subchoanitic, septal necks and thin connecting rings that may expand slightly into the chambers.

Organic deposits that are formed within consist of either ring-like annuli restricted to the septal openings or which extend toward the front along the next connecting ring.

Cameral deposits, which are generally well developed, are formed along the front and backside of the septa, referred to as episeptal and hyposeptal.