Turricaspia pulla (B. Dybowski & Grochmalicki, 1915)

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

Turricaspia pulla (B. Dybowski & Grochmalicki, 1915) Fig. 14A-J

Turricaspia pulla *1915 Micromelania (Turricaspia) caspia Eichw. var. pulla nov. var.; B. Dybowski & Grochmalicki: 111, pl. 1, fig. 6a.

Turricaspia pulla 1917 Micromelania (Turricaspia) caspia Eichw. var. pulla nov. var. - B. Dybowski & Grochmalicki: 10, pl. 1, fig. 7.

Turricaspia pulla 1969 Pyrgula [( Turricaspia )] Pyrgula pulla (Dyb. et Gr.). - Logvinenko & Starobogatov: 361-362, fig. 360 (8).

Turricaspia pulla 2006 Pyrgula pulla (B. Dybowski et Grochmalicki, 1915). - Kantor & Sysoev: 102, pl. 46, fig. C.

Turricaspia pulla 2016 Pyrgula pulla (B. Dybowski et Grochmalicki, 1915). - Vinarski & Kantor: 242.

Material.

186 specimens ( RGM 1309803 , RGM 1309804 , RGM 1309820 , RGM 1310211 , RGM 1310253 -1310254, LV 201519 ) .

Type material.

Lectotype: ZIN 4422/1 (specimen illustrated by B. Dybowski and Grochmalicki 1915, 1917), designated by Logvinenko and Starobogatov (1969), illustrated by Kantor and Sysoev (2006: pl. 46, fig. C).

Type locality.

Caspian Sea (no locality specified).

Dimensions.

4.88 × 2.10 mm ( LV 201519, Fig. 14A-C ); 5.17 × 2.11 mm ( RGM 1310254, Fig. 14D, I, J ); 4.77 × 1.90 mm ( RGM 1310253, Fig. 14E-G ); 5.84 × 2.16 mm ( RGM 1309803); 5.54 × 1.97 mm ( RGM 1309804).

Description.

Slender conical shell with up to 8 whorls. Protoconch bulbous, weakly granulate, with striae on second half; diameter 410 µm, consists of 1.25 whorls; nucleus low, broad, 140 µm wide; transition to teleoconch distinct. Teleoconch whorls weakly convex, with maximum convexity at or slightly below midline of whorl profile; portion above maximum convexity almost straight-sided, portion below weakly convex. Whorls are separated by deep suture. Height of last whorl amounts 45% of total shell. Sometimes intentions of spiral lines appear on lower half of last whorl. Aperture ovoid, oblique, with weakly thickened and slightly expanded peristome; in lateral view, peristome is distinctly sigmoidal, with broad, shallow indentation in upper half and broad, weak protrusion in lower half. Umbilicus very narrow or closed. Growth lines sigmoidal, markedly prosocline in upper half, weakly opisthocline in lower half.

Discussion.

The species can be easily distinguished from most other species of Turricaspia by its comparably broad conical shape, the low-convex whorls, and its small size. Juvenile specimens of T. meneghiniana remind of T. pulla but the former have broader shells with more convex whorls. Turricaspia pullula is likewise broader and exposes a characteristic tripartite whorl profile (see below).

Distribution.

Endemic to the Caspian Sea, reported from middle and south Caspian Sea at depths between 15 and 75 m ( Logvinenko and Starobogatov 1969).

Figures

Figure 14. Pyrgulinae. A-C Turricaspia pulla (B. Dybowski & Grochmalicki, 1915), LV 201519 D, I, J T. pulla, RGM 1310254 E-G T. pulla, RGM 1310253 H T. pulla, RGM 1309820 K, L Turricaspia pullula (B. Dybowski & Grochmalicki, 1915), RGM 1310210.