Turricaspia pullula (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 pullula (B. Dybowski & Grochmalicki, 1915) Fig. 14K, L

Turricaspia pullula *1915 Micromelania (Turricaspia) caspia Eichw. var. pullula nov. var.; B. Dybowski & Grochmalicki: 111-112, pl. 1, fig. 7.

Turricaspia pullula 1917 Micromelania (Turricaspia) caspia Eichw. var. pullula nov. var. - B. Dybowski & Grochmalicki: 10-11, pl. 1, fig. 8.

Turricaspia pullula 1969 Pyrgula [( Turricaspia )] Turricaspia pullula (Dyb. et Gr.). - Logvinenko & Starobogatov: 366-367, fig. 363 (3).

Turricaspia pullula 2006 Turricaspia pullula (B. Dybowski et Grochmalicki, 1915). - Kantor & Sysoev: 109, pl. 50, fig. B.

Turricaspia pullula 2016 Turricaspia pullula (B. Dybowski et Grochmalicki, 1915). - Vinarski & Kantor: 249.

Material.

1 damaged specimen ( RGM 1310210 ) .

Type material.

Lectotype: ZIN 4423/1 (specimen illustrated by B. Dybowski and Grochmalicki 1915, 1917), designated by Logvinenko and Starobogatov (1969), illustrated by Kantor and Sysoev (2006: pl. 50, fig. B) .

Type locality.

Caspian Sea (no locality specified).

Dimensions.

5.36 × 2.62 mm.

Description.

A single incomplete specimen of about 6 whorls is preserved. Protoconch is corroded beyond recognition. Early teleoconch whorls are poorly convex to centrally flattened. Convexity strongly increases on about 3rd whorl. From 4th whorl onwards, whorl surface is partitioned into three zones: two lower zones are roughly straight-sided in profile, upper one slightly concave; middle zone slightly wider than other two; zones are separated by blunt angulations, whose expression varies between very faint to distinct (but no keel is formed). Aperture not preserved, but the tight coiling of the last preserved whorl suggests that umbilicus is absent. Growth lines strongly prosocline in upper third, near orthocline in lower two-thirds; transition coincides with boundary between upper and middle zone.

Discussion.

The available specimen corresponds well to the lectotype as illustrated by Kantor and Sysoev (2006). The very characteristic tripartite whorl profile is only discernible on the penultimate whorl of their specimen. Such a pattern is unknown for any other Pontocaspian Pyrgulinae .

Distribution.

Endemic to the Caspian Sea, reported from the western part of the middle Caspian Sea at a depth of 60 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.