pars 1949 Cravenoceras nevadense .- Youngquist, pars, pl.58, 59, 60, 62, 64 (teste Titus, 2000),
pars ----- Cravenoceras hesperium.- Youngquist, pars, pl.59, 60, 62.
2000 Eosyngastrioceras quadratum Titus: 39, text-fig.32, pl.10 fig.1-17.

Holotype USNM 120617, Gordon,1964,pl.3 fig.3-5.

See Fig.TAX6566 A-D (sutures), E (cross-section].

Eosyngastrioceras quadratum differs from E.inexpectans n. sp. and E. imprimum (Saunders) in that the two latter species do not have strap-like lamellae at diameters of greater than 15 mm.

E. imprimum is also more cadiconic in early growth stages. Eosyngastrioceras quadratum is less involute and has a wider umbilicus than in Eosyngastrioceras hesperium. The ventral lobe of E. quadratum is generally wider than that of E. hesperium