Ocinebrinopsis subnuda, Harzhauser & Landau & Merle, 2025

Ocinebrinopsis subnuda sp. nov.

Figs 29 View FIGURE 29 , 38A–D View FIGURE 38

Type material. Holotype: NHMW 2024 View Materials /0048/0001, SL: 20.6 mm, MD: 11.7 mm, Mattersburg ( Austria), Figs 38A View FIGURE 38 1 – A View FIGURE 1 3 View FIGURE 3 . Paratypes: NHMW 2024 View Materials /0048/0002, SL: 20.5 mm, MD: 12.1 mm, Mattersburg ( Austria), Figs 38B View FIGURE 38 1 –B View FIGURE 1 3 View FIGURE 3 . NHMW 2024 View Materials /0048/0003, SL: 19.0 mm, MD: 11.7 mm, Mattersburg ( Austria), Figs 38C View FIGURE 38 1 –C View FIGURE 1 3 View FIGURE 3 . NHMW 2024 View Materials /0048/0004, SL: 19.1 mm, MD: 11.4 mm, Mattersburg ( Austria), Figs 38D View FIGURE 38 1 –D View FIGURE 1 3 View FIGURE 3 .

Additional material. 30 spec., NHMW 1846 View Materials /0037/0224, Mattersburg ( Austria) .

Type locality. Mattersburg ( Austria) .

Type stratum. Baden Formation.

Age. Middle Miocene, middle Badenian (Langhian).

Etymology. nudus, Latin for naked, referring to the reduced sculpture.

Diagnosis. Small, biconic shell with weak tubercles above abapical suture on spire whorls and weakly shouldered last whorl with broad, low, flattish primary and secondary cords, characterized by thin outer lip with weak to subobsolete denticles and open siphonal canal; P6 not developed.

Description. Small, biconical shell; apical angle ~57–68°. Protoconch unknown. Teleoconch of up to five whorls. Suture weakly incised, linear. Early teleoconch whorls convex, weakly shouldered with eight prominent axial ribs overrun by faint IP and prominent P1. Later spire whorls with broad, moderately steep, concave subsutural ramp. Axial ribs fading over subsutural ramp. IP and P1 almost coalescent, forming weak tubercles over axial ribs, just above abapical suture. Spiral sculpture reduced. Last whorl attaining ~80% of total height; broad, steep, weakly concave subsutural ramp, rounded shoulder, moderately constricted below. Axial sculpture of nine low, broad, weak axial ribs, most prominent along shoulder. Spiral sculpture of weak subsutural cord coalescent with broad adis; IP and abis broad, flat, separated by narrower interspaces. P1–P6, ADP, MP forming broad, flattish cords; s1–s4 and ms only slightly narrower; primary and secondary cords separated by narrow, relatively shallow grooves. Fasciole moderately swollen, delimiting broad, shallow pseudoumbilicus. Aperture ovate, outer lip not thickened with weak to subobsolete, wide-spaced ID, D1–D5 placed some distance behind peristome.Anal canal weakly incised; siphonal canal moderately short, wide, open, weakly bent to the left. Columella broadly excavated, smooth, faintly twisted at siphonal canal. Columellar callus forming indistinct adherent rim.

Discussion. In the NHMW collections, specimens have been mixed with other Ocinebrinopsis species, such as O. credneri (Hoernes & Auinger, 1885) and O. orientalis (Friedberg 1928) . The comparatively stouter, ovate outline and the open siphonal canal distinguish Ocinebrinopsis subnuda sp. nov. clearly from O. credneri and O. orientalis , which both have much more prominent denticles in the outer lip. The reduced sculpture and broad spiral cords are reminiscent of Ocinebrinopsis grundensis (Hoernes & Auinger, 1885) , which differs in its much larger size and more bifid labial denticles D1–D6.

Paleoenvironment. Unknown. The preservation suggests an allochthonous origin from shallow marine environments because the specimens differ from the autochthonous shells from offshore clays typically found at Mattersburg.

Distribution in Central Paratethys. Badenian (Middle Miocene): Eisenstadt-Sopron Basin: Mattersburg ( Austria) (hoc opus).