Bittium rossicum, Harzhauser & Guzhov & Landau, 2025

Bittium rossicum sp. nov.

Figs 20A–G View FIGURE 20

Cerithium (Bittium) scabrum Olivi— Mikhailovsky 1903: 51 View in CoL , pl. 3, figs 19–22 [non Bittium scabrum (Olivi, 1792) View in CoL ].

Bittium reticulatum deforme — Özsayar, 1977: 61, pl. 10, fig. 1 [non Bittium deforme ( Eichwald, 1829) ].

Bittium (Bittium) reticulatum View in CoL ( Costa, 1778)— Iljina 1993: 67, pl. 8, figs 6–7 [non Bittium reticulatum View in CoL ( da Costa, 1778)].

Bittium scabrum (Olivi) View in CoL —Barg & Stepanyak 2005: 151, pl. 14, figs 7–8 [non Bittium scabrum (Olivi, 1792) View in CoL ].

Bittium reticulatum reticulatum View in CoL ( Costa, 1778)— Guzhov 2022: pl. 3, figs 10–15, pl. 4, figs 2–6 [non Bittium reticulatum View in CoL ( da Costa, 1778)].

Type material. Holotype: PIN 5794 View Materials /38, SL: 5.7 mm, MD: 1.9 mm, Shirvanskaya ( Russia), Tarkhanian, Middle Miocene, Figs 20B View FIGURE 20 1 –B View FIGURE 1 3 View FIGURE 3 . Paratypes: PIN 5904 View Materials /15, SL: 7.4 mm, MD: 2.4 mm, Shirvanskaya ( Russia), Tarkhanian, Middle Miocene, Fig. 20A View FIGURE 20 . PIN 5794 View Materials /41, SL: 4.8 mm, MD: 1.9 mm, Shirvanskaya ( Russia), Tarkhanian, Middle Miocene, Fig. 20C View FIGURE 20 . PIN 5794 View Materials /42, SL: 5.3 mm, MD: 1.9 mm, Kutais ( Russia), Tarkhanian, Middle Miocene, Fig. 20D View FIGURE 20 . PIN 5794 View Materials /49, SL: 4.8 mm, MD: 2 mm, Belaya River ( Russia), early Chokrakian, Middle Miocene, Figs 20E View FIGURE 20 1 –E View FIGURE 1 2 View FIGURE 2 . PIN 5794 View Materials /48, SL: 5.8 mm, MD: 2.5 mm, Belaya River ( Russia), early Chokrakian, Middle Miocene, Figs 20F View FIGURE 20 1 –F View FIGURE 1 3 View FIGURE 3 . PIN 5904 View Materials / 16, Belaya River ( Russia), early Chokrakian, Middle Miocene, Fig. 20G View FIGURE 20 .

Type locality. Shirvanskaya ( Russia) .

Type stratum. Aleuritic clays.

Age. Middle Miocene, Tarkhanian (Langhian).

Etymology. Referring to Russia.

Diagnosis. Small, moderately stocky shell with low conical protoconch of 2.5 convex whorls, seven to nine teleoconch whorls, sculpture of four spiral cords with small tubercles, axial sculpture strongly reduced, without varices.

Description. Small, moderately stocky shell of seven to nine teleoconch whorls, attaining 6–7 mm in height; apical angle 30–36°. Protoconch low conical of 2.5 convex, probably smooth whorls, terminating in sinusigera (dp = 280 μm). Early teleoconch whorls bicarinate, angled; later teleoconch whorls regularly convex. Suture moderately incised, linear.First teleoconch whorl with two prominent spiral cords placed mid-whorl, partially visible suprasutural cord. First secondary spiral cord appears below suture on second teleoconch whorl and quickly becomes equal in strength to primary cords. Second secondary cord appears below first secondary, strongly variable in appearance. Late teleoconch whorls convex, with four subequal, evenly spaced, tuberculate to almost beaded spiral cords. Axial sculpture more prominent on early and mid-spire whorls, weakening to subobsolete and more numerous on last two whorls; 17–21 axial ribs on penultimate whorl. Last whorl convex, slightly inflated, attaining 40–47% of total height. Varices absent. Transition into base convex with two moderately weak, widely spaced peribasal cords and about four even weaker cords over base and fasciole. Aperture wide, ovate. Columella excavated. Columellar callus forming thin, narrow rim, Anal canal indistinct. Outer lip thin. Siphonal canal very short, wide.

Discussion. The variability of this subspecies was discussed in detail by Guzhov (2022) (as Bittium reticulatum reticulatum ). Bittium rossicum differs from B. tschokrakense ( Özsayar, 1977) mainly in its evenly convex whorls due to more frequent spiral cords, four equal spiral cords, and less prominent and smaller tubercles.

Paleoenvironment. Shallow marine, inner neritic ( Guzhov 2022).

Distribution. Tarkhanian and early Chokrakian (Middle Miocene) of the Eastern Paratethys Sea.

Eastern Paratethys. Tarkhanian (Middle Miocene): Turkey:Arabadurağı (Sinop District) ( Guzhov 2022); Black Sea Lowland : Kam’yanka, Tomakivka (Dnipropetrovsk Region, Ukraine) (Barg & Stepanyak 2005); Ciscaucasia : Damanka, Khadyzhensk, Kutais, Shirvanskaya (Krasnodar Krai, Russia) ( Guzhov 2022).

Early Chokrakian (Middle Miocene): Ciscaucasia : Belaya River (Adygea), Khadyzhensk, Kutais, Shirvanskaya (Krasnodar Krai), Novo-Kuvinsk (Karachay-Cherkessia), Yaman-Dzhalga (Stavropol Krai, Russia); Transcaucasia : Dzhgali ( Georgia); Transcaspian Region: southern Mangyshlak ( Kazakhstan) ( Guzhov 2022).