Ocenebra schoenni (Hornes, 1853)

Ocenebra schoenni Group

Discussion. This group comprises species with a gradate spire, broad, shallow subsutural ramp, prominent axial ribs and raised primary spiral cords. The aperture is narrow, with thickened, straight-sided outer lip bearing prominent denticles within, and the siphonal canal is fused in fully grown specimens. We place Ocenebra schoenni (Hörnes, 1853) and Ocenebra confluens ( Eichwald, 1830) in this group, which originated in the Paratethys Sea during the Egerian (Late Oligocene) and persisted there into the Badenian (Middle Miocene).

The Ocenebra schoenni group is reminiscent of the Caribbean genus Eupleura H.Adams &A.Adams, 1853 [type species Ranella caudata Say, 1822 ; present-day, western Atlantic], but Eupleura has only two varices. It displays stronger similarities with some morphotypes of Atlanto-Mediterranean species Ocenebra edwardsi ( Payraudeau, 1826) , see Crocetta et al. (2020: fig. 2C).