Euspira amitrovi, Harzhauser & Landau & Guzhov, 2025

Euspira amitrovi nov. sp.

Figs 34A–C View FIGURE 34 , 35A View FIGURE 35

? Natica millepunctata Lmk.— Mikhailovsky 1903: 61 View in CoL , 222, pl. 4, figs 16–19 [ non Natica millepunctata Lamarck, 1822 View in CoL = Naticarius stercusmuscarum ( Gmelin, 1791) View in CoL ].

Natica millepunctata Lamarck, 1822 View in CoL — Volkova 1955: 36 ( pars), pl. 22, fig. 5 [ non Natica millepunctata Lamarck, 1822 View in CoL = Naticarius stercusmuscarum ( Gmelin, 1791) View in CoL ].

Natica millepunctata Lamarck, 1822 View in CoL — Volkova 1974: 93 ( pars), pl. 11, fig. 5 [ non Natica millepunctata Lamarck, 1822 View in CoL = Naticarius stercusmuscarum ( Gmelin, 1791) View in CoL ].

? Natica millepunctata Lmck.— Zhgenti 1981: 162 View in CoL , pl. 10, fig. 1 [ non Natica millepunctata Lamarck, 1822 View in CoL = Naticarius stercusmuscarum ( Gmelin, 1791) View in CoL ].

? Natica ( Nacca) millepunctata Linné— Zhgenti 1991: 72 View in CoL , pl. 42, fig. 8 [ non Natica millepunctata Lamarck, 1822 View in CoL = Naticarius stercusmuscarum ( Gmelin, 1791) View in CoL ].

Type material. Holotype: PIN 5904 View Materials /115, SL: 14 mm, MD: 14.4 mm, Belaya River , Russia, Middle Miocene, Tarkhanian, Figs 34A View FIGURE 34 1 –A View FIGURE 1 4 View FIGURE 4 , 35A View FIGURE 35 1 –A View FIGURE 1 2 View FIGURE 2 . Paratypes: PIN 5904 View Materials /116, SL: 11.7 mm, MD: 11.6 mm, Novo-Kuvinsk , Russia, Middle Miocene, Tarkhanian, Figs 34B View FIGURE 34 1 –B View FIGURE 1 4 View FIGURE 4 . PIN 5904 View Materials /117, SL: 14.7 mm, MD: 14.7 mm, Otradnaya , Russia, Middle Miocene, Tarkhanian, Figs 34C View FIGURE 34 1 –C View FIGURE 1 4 View FIGURE 4 .

Type locality. Belaya River , Russia .

Type stratum. Aleuritic clay.

Age. Middle Miocene, Tarkhanian (Langhian).

Etymology. In honor of Oleg V. Amitrov, explorer of Paleogene gastropods.

Diagnosis. Small, robust, globose shell with moderately low conical spire, narrow subsutural shelf, moderately expanding last whorl, wide and deep umbilicus, fully reduced funicle; strongly thickened parietal callus fused with solid, elongate-trigonal umbilical callus.

Description. Small, robust, globose shell of five whorls (SL/MD = ~1.0). Embryonal shell of less than one whorl, spirally sculptured. Number of protoconch whorls unknown. Spire moderately low conical; apical angle 118– 133°. Suture linear, narrowly incised. Teleoconch whorls with narrow, weakly concave subsutural shelf. Shoulder angulation absent to faint. Last whorl moderately expanding, attaining ~95% of total height. Periphery placed just below mid-whorl (~45%). Growth lines distinct and weakly prosocyrt in apical view, most prominent at adapical suture, weak at periphery. Several prominent growth lines occur on terminal third of last whorl. Aperture wide, Dshaped, prosocline. Position of adapical tip of aperture moderately high (~80–85%), distinctly above mid-whorl. Aperture attaining ~75–77% of total height. Columellar lip broad, strongly reinforced; basal lip solid, outer lip moderately thin. Columellar angle ~12–17°. Opercular ridge in outer lip subobsolete. Umbilicus wide (~17%), deep with prominent growth lines, with rounded or weakly angled periphery. Parietal callus long (~50%), strongly thickened, with prominent swelling at adapical tip, with straight to weakly concave margin, not expanding over base. Anterior lobe of parietal callus thick, narrow. Funicle not visible. Umbilical callus elongate trigonal, fused with parietal callus. Basal fasciole broad, rounded. No color pattern preserved. Operculum unknown.

Discussion. Euspira amitrovi nov. sp. is a very rare Tarkhanian naticid of the Eastern Paratethys, which occurs together with Euspira protracta ( Eichwald, 1830) . It is superficially reminiscent of Cochlis degregorioi nov. sp. from the Central Paratethys but differs in its robust, umbilical callus, which is fused with the columellar callus and in its reduced funicle. The Early Miocene Cochlis gebhardti nov. sp. has a similar umbilicus with broad, low funicle but has a weaker parietal callus and its last whorl is more expanding.

Zhgenti (1991: pl. 42, fig. 8) illustrated a late Konkian shell from Privol’nyi, which was originally illustrated in Zhgenti (1981: pl. 10, fig. 1) as Chokrakian shell deriving from Sychevaya Mountain near Khopersk (rightly Michurinskii, earlier known as Khoperskii). The first interpretation seems to be correct because the shell indeed looks like Euspira amitrovi and Sychevaya Mountain is known as Chokrakian locality with numerous redeposited Tarkhanian shells.

Paleoenvironment. Shallow marine, inner neritic.

Distribution in Central Paratethys. Tarkhanian (Middle Miocene): Ciscaucasia : Belaya River ( Adygea), Novo-Kuvinsk ( Karachay-Cherkessia), Otradnaya ( Krasnodar Krai), Yaman-Dzhalga ( Stavropol Krai, Russia); Transcaucasia : Dzhgali ( Georgia) ( hoc opus).