Rhiphaeoceratidae

• Rhiphaeoceras: a riphaeoceritid first found the south Urals with an oval whorl section; flanks with faint, narrow radial ribs; suture with broad ventral saddle and deep dorsal lobe.
• Pararhiphaeoceras: a riphaeoceratid with a subtrapezoidal whorl section, widest across the venter, narrowing to the dorsum; flanks with short oblique ribs; suture as for Rhiphaeoceras. Found in L Permian in Azerbaijan and Tajikistan.
• Rhiphaeonautilus: a riphaeoceratid like Pararhiphaeoceras, with a subtrapezoidal whorl section, but with short inflated ribs on the lateral areas and with a shallow lobe modifying the ventral saddle. Also first found in the south Urals, as with Rhiphaeoceras.
• Skolakoceras: a riphaeoceratid with a subquadrate whorl section, venter and sides flattened, lateral areas bearing slightly oblique ribs. The suture is similar to that of Rhiphaeonautilus, with a broad ventral saddle modified by a shallow lobe.