Hercoglossidae
Introduction '''Hercoglossidae''' is a family of nautilid cephalopods in the superfamily Nautilaceae. It was established by Spath in 1927 for smooth, involute nautiloids characterized by a suture with differentiated elements, known from the Upper Jurassic to the Oligocene. ''Hercoglossa danica'' fossil Four genera are described in the Treatise. They are ''Hercoglossa'', ''Aturoidea'', ''Cimonia'', and ''Deltoidonatilus''. All have a whorl section that is generally rounded, except for ''Deltoidonatilus'' where in it is triangular in outline. Sutural complexity increases from ''Cimomia'' to ''Hercoglossa'' and to ''Aturoidea''. The suture in ''Deltoidonautilus'' is like than in ''Hercoglossa''. ''Cimomia'', which intergrades with ''Eutrephoceras'', is the earliest and makes its first appearance in the Upper Jurassic. ''Eutrephoceras'' is assigned to the Nautilidae which includes ''Nautilus''. ''Hercoglossa'', which is derived from ''Cimomia'', first appears in the Lower Cretaceous and is followed stratigraphically by ''Aturoidea'' and ''Deltoidonautilus'' which first appear in the Upper Cretaceous. ''Aturoidea'' is the progenitor of ''Aturia'' (of the monotypic Aturidae), to which it gave rise in the Paleocene.
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