Nitidiscala baluki, Harzhauser & Landau, 2025

Nitidiscala baluki sp. nov.

Figs 4I View FIGURE 4 , 33H View FIGURE 33 , 37A View FIGURE 37 1 –A View FIGURE 1 2 View FIGURE 2

Scala (Clathrus) exspectata (De Boury, 1913) View in CoL — Bałuk 2006: 202, pl. 10, fig. 2 [non ‘Epitonium’ exspectatum (de Boury, 1913) = ‘ Epitonium View in CoL ’ subscalare (d’Orbigny, 1852)].

Type material. Holotype, NHM 1876/0011/0083, SL: 3.1 mm, MD: 1.7 mm, Lăpugiu de Sus ( Romania), Figs 4I View FIGURE 4 , 33H View FIGURE 33 , 37A View FIGURE 37 1 –A View FIGURE 1 2 View FIGURE 2 .

Type locality. Lăpugiu de Sus ( Romania), Făget Basin .

Type stratum. Silt and clay of the Dej Formation.

Age. Middle Miocene, Badenian (Langhian).

Etymology. In honor of Wacław Bałuk (1935–2022), (University Warsaw, Poland), in recognition of his contributions on Paratethyan paleontology.

Diagnosis. Very small, moderately broad, stocky shell with low spire, globose last whorl and thin, strongly raised lamellae obliquely aligned axially, without being fused at deeply impressed suture.

Description. Shell very small, moderately broad, stocky with relatively low spire and globose last whorl (apical angle 46°). Protoconch high conical of 3.5 smooth, moderately convex whorls with elevated blunt nucleus. Teleoconch of three strongly convex whorls. Sculpture of thin, strongly raised lamellae, obliquely aligned axially without being fully fused, indented at deeply impressed suture (10: 12: 13), crests erect. No spiral sculpture. Last whorl attaining 60% of total height, no basal angulation nor peribasal cord but lamellae slightly angled at transition to base, lamellae grading into prominent, relatively broad ribs terminating at columellar callus, base weakly convex. Fasciole very short, very broad with prominent growth lines. Aperture ovate, columella weakly concave. Outer lip strongly thickened by varix. Columellar callus forming broad rim, attached to base, parietal callus delicate. Peristome duplex. No umbilicus.

Discussion. This species was confused by Bałuk (2006) with ‘ Epitonium ’ exspectatum (de Boury, 1913) [= ‘ Epitonium ’ subscalare (d’Orbigny, 1852)]. The type specimen of ‘ Epitonium ’ exspectatum, from the Aquitanian of Saint Avit ( France), differs from Nitidiscala baluki sp. nov. in its much larger size (SL: 6 mm), wider last whorl with broader subsutural ramp, and the more prominent lamellae (see de Boury 1913 a: pl. 8, fig. 14). ‘ Epitonium ’ subscalare (d’Orbigny, 1852, as understood by Lozouet et al. (2001), from the Aquitanian and Burdigalian of Dax and Saucats ( France), is also much larger (SL: 14 mm) and differs in its higher spire, the comparatively thinner and more orthocline lamellae and the peribasal cord and is therefore not congeneric (see Cossmann & Peyrot 1922: pl. 4, figs 39–40; Lozouet et al. 2001: pl. 19, fig. 5). ‘ Gyroscala’ series de Boury, 1913 from the Burdigalian of Saint- Jean-de-Marsacq ( France), is reminiscent of N. baluki and falls within the same size-range, but differs in its thinner lamellae, which are more fused at the suture and it has a delicate peribasal cord (see de Boury 1913 a: pl. 8, fig. 16). Nitidiscala baluki differs from Nitidiscala connexicosta sp. nov. in its globose last whorl and even thinner varices, which are erect.

The extant Connexiscala cultellicosta de Boury, 1913 is superficially similar but is stockier and differs in its more numerous lamellae (see de Boury 1913 a: pl. 8, fig. 17).

Distribution in Central Paratethys. Badenian (Middle Miocene):? Korytnica Basin: Korytnica ( Poland) ( Bałuk 2006); Făget Basin: Lăpugiu de Sus ( Romania) (hoc opus).