1957  Hyattoceratinae Miller & Furnish: L53.
     1960  Marathonitinae.-Ruzhentsev: 226.
     1962  Marathonitinae.-Osnovy: 391.
     1978  Hyattoceratinae.- Bogoslovskaia: 58.
     1987  Hyattoceratidae.-Glenister & Furnish: 987 [nom.transl. ex Hyattoceratinae].
     2002  Hyattoceratidae.-Leonova: S90.

[Bogoslovskaia, 1978, p. 58]: Shell pachyconic or subdiscoidal, with high whorls, and usually irregularly shaped in
the terminal stage, heart-shaped or suboval. Umbilicus ranging from very narrow to closed on account of appreciable
thickening of the shell layer in the region of the umbilical border. Ornament represented by lamellae and costellae
forming a broad, frequently deep ventral sinus. Suture consisting of 20 to 24 lobes. Branches of ventral lobe broad,
bicuspid and tricuspid, except for the genus Peritrochia, which has comparatively narrow branches that are basally
simple. Outer lateral lobes ranging from tricuspid to multipetaloid. Dorsal lobe narrow and tricuspid or simple and hastate.
Inner lateral lobes bicuspid or simple.

Orenburgian-Capitanian stages.

Distinguished from the Kargalitinae and the Marathonitinae by the structure of the shell in the umbilical region - by the
appreciable thickening of the shell layer along the umbilical border; by the direction of the transverse costellae and
lamellae, which form a broad and deep ventral sinus. Additionally distinguished from Kargalitinae by the tricuspid or
multicuspid first outer lateral lobe, instead of bicuspid.[Glenister & Furnish, 1987, p. 987]: Hyattoceratidae are  distinctive
advanced marathonitaceans characterized by 20-24 sutural elements and complex but irregular phylloid serration of
the external lateral lobes. Consistent serration throughout the lineage warrants full familial status. The conch is discoidal,
with small to closed umbilicus, and lacks conspicuous sculpture. Mature  modifications occur in advanced forms and
include geniculate coiling, modifications in whorl section, and penultimate constriction followed by a terminal flare of the
ventral peristome. Spectacular dimorphism has been suggested (Davis et al., 1969).