Laevicaspia vinarskii, Neubauer & Velde & Yanina & Wesselingh, 2018

Neubauer, Thomas A., Velde, Sabrina van de, Yanina, Tamara & Wesselingh, Frank P., 2018, A late Pleistocene gastropod fauna from the northern Caspian Sea with implications for Pontocaspian gastropod taxonomy, ZooKeys 770, pp. 43-103 : 43

Laevicaspia vinarskii sp. n. Fig. 10F-J, L-M, O

Type material.

Holotype: LV 201517 ; 3.70 × 1.72 mm (Fig. 10F-G ). Paratypes: RGM 1309821 ; 3.34 × 1.48 mm (Fig. 10I, J, L, M ). RGM 1309805 ; 3.61 × 1.54 mm (Fig. 10H, O ). LV 201731 ; 4.14 × 1.93 mm.

Additional material.

5 specimens ( RGM 1309793 , LV 201732 ) .

Type locality.

Selitrennoye, Astrakhan, Russia; northern Caspian Basin; GPS coordinates: 47°10'21.19"N, 47°26'25.41"E ( WGS 84).

Age.

Early Late Pleistocene (late Khazarian, MIS 5).

Etymology.

In honor of Maxim Vinarski (Saint Petersburg State University) for his contributions to Malacology.

Diagnosis.

Slender ovoid, imperforate shell with up to 6.5 moderately convex whorls, narrow suture, granulate-striate protoconch, high whorl expansion rate and small, adnate, inclined aperture.

Description.

Slender ovoid shell with up to 6.5 whorls. Protoconch consists of 1.2 whorls measuring 375 µm; nucleus is 140 µm wide; surface strongly granulate on nucleus, less so on remaining protoconch, striae appear on last 0.25 whorls; P/T transition marked by distinct growth rim. Teleoconch whorls moderately convex, separated by narrow suture; whorls increase slowly in height, with the last attaining 53-57% of shell height, passing into weakly convex base. Weak subsutural band is observed in one specimen. Aperture small, inclined, closely attached to base of preceding whorl, leaving no or slit-like umbilicus. Peristome slightly thickened, especially at adapical tip; regularly sinuate in lateral view, with broad adapical indentation and about equally broad and high abapical protrusion. Distinct spiral furrows occur in well preserved specimens. Growth lines weak, prosocline in upper half, orthocline in lower half.

Discussion.

The new species differs from co-occurring Laevicaspia kolesnikoviana in the higher whorl expansion rate at about the same size and the larger aperture. Laevicaspia? ismailensis (Golikov & Starobogatov, 1966) from lakes Yalpug and Kugurlu in the Danube river delta is more slender and larger (5.6 mm) at the same number of whorls and has a less inclined, rounder aperture (see holotype illustrated by Kantor and Sysoev 2006: pl. 50, fig. A).

Distribution.

Endemic to the Caspian Sea Pleistocene, so far only known from Selitrennoye.

Figures

Figure 10. Pyrgulinae. A-C, K Laevicaspia kolesnikoviana (Logvinenko & Starobogatov in Golikov & Starobogatov, 1966), RGM 1309816 D L. kolesnikoviana, LV 201516 E, N L. kolesnikoviana, RGM 1309819 F, G Laevicaspia vinarskii sp. n., holotype, LV 201517 H, O L. vinarskii sp. n., RGM paratype, 1309805 I, J, L, M L. vinarskii sp. n., paratype, RGM 1309821.