Rodzaj Diarthema Piette, 1864
Gatunek typowy Opis The whorls of the relatively wide spire have a smooth protoconch and later ornament of strong spiral ribs and median corner or keel that may bear short axial ribs. The spiral ribs continue into the outer lip forming a spike with it an posterior outer short gutter-like extension. The body whorl is somewhat deformed by one or two varices in front of the outer lip, the first one about half a whorl back. A large posterior outer thorn, a smaller basal thorn and a narrow channel-like siphon (like Monocuphus). Shell shape and shell ornament is similar to Monocuphus but the outer lip more expanded with several short spikes the largest of which lies on the posterior margin. Strong varix on the body whorl about half a whorl in front of the final aperture. Synonimy Zasięg czasowy Jurassic Literatura Piette, E. 1864. Paléontologie française, terrains jurassiques. Tome III. Gastéropodes. 535 pp. Masson, Paris. |
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