Turricaspia andrussowi (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 andrussowi (B. Dybowski & Grochmalicki, 1915) Fig. 11A, B

Turricaspia andrussowi *1915 Micromelania ( Turricaspia ) Andrussowi nov. sp.; B. Dybowski & Grochmalicki: 125-126, pl. 3, figs 31a-b.

Turricaspia andrussowi 1917 Micromelania ( Turricaspia , Trachycaspia ) Andrussowi nov. sp. - B. Dybowski & Grochmalicki: 26-27, pl. 4, fig. 39.

Turricaspia andrussowi 1969 Pyrgula [( Turricaspia )] Pyrgula andrusovi [sic] (Dyb. et Gr.). - Logvinenko & Starobogatov: 365-366, fig. 362 (4) [partim].

Turricaspia andrussowi 2006 Turricaspia andrussowi (B. Dybowski et Grochmalicki, 1915). - Kantor & Sysoev: 104-105, pl. 48, fig. A [partim].

Turricaspia andrussowi 2016 Turricaspia andrussowi (B. Dybowski et Grochmalicki, 1915). - Vinarski & Kantor: 245 [partim].

Material.

3 spire fragments ( RGM 1309814 , RGM 1310205 ) .

Type material.

Lectotype: ZIN 4355 /1 (specimen illustrated by B. Dybowski and Grochmalicki 1915, 1917), designated by Logvinenko and Starobogatov (1969), illustrated by Kantor and Sysoev (2006: pl. 48, fig. A) .

Type locality.

Caspian Sea (no locality specified).

Description.

Available fragments indicate very slender, conical shell. Apex broad, blunt, bulbous. Whorl profile flattened, very weakly spruce-like, with straight-sided upper two-thirds passing over convexity into weakly convex lower third; in addition, broad, flat subsutural band appears, sometimes accompanied by very narrow concavity below. Umbilicus seems fully closed. Aperture not preserved in any specimen.

Discussion.

The identification of the three spire fragments rests upon the strongly adpressed whorls with very narrow suture and the flattened, spruce-like whorl profile, and the large, bulbous protoconch. Turricaspia eulimellula (B. Dybowski & Grochmalicki, 1915) has a similarly slender spire with adpressed whorls, but it bears a basal keel and the maximum whorl convexity is around mid-height instead of in the lower third. Turricaspia grimmi (Clessin & W. Dybowski in W. Dybowski, 1887) differs in its perfectly straight-sided, rectangular, very weakly stepped whorl profile (see also B. Dybowski and Grochmalicki 1917, pl. 3, figs 34-35; Kantor and Sysoev 2006, pl. 46, fig. L).

A very similar species is Pyrgula dubia Logvinenko & Starobogatov, 1969 from the middle Caspian Sea, matching the present one in the weakly spruce-like whorl profile; in fact, it might just be a juvenile specimen of T. andrussowi . Similarly, Pyrgula turkmenica Logvinenko & Starobogatov, 1969, from the eastern part of southern Caspian Sea, corresponds to T. andrussowi in the weak subsutural band accompanied by an abapical concavity; it might as well be a juvenile representative of T. andrussowi .

Logvinenko and Starobogatov (1969) synonymized without discussion Hydrobia spica sensu Grimm, 1876, Turricaspia elegantula sensu B. Dybowski & Grochmalicki, 1915, T. brusinae (B. Dybowski & Grochmalicki, 1915), as well as several varieties of T. spica and T. turricula described by B. Dybowski & Grochmalicki (1915), with T. andrussowi (see also Kantor and Sysoev 2006, Vinarski and Kantor 2016). However, none of these taxa actually resembles T. andrussowi . This species can be well delimited from these alleged synonyms in its bulbous protoconch and the characteristic, weakly spruce-like whorl profile. (Note that the drawing provided by Logvinenko and Starobogatov 1969 shows a rather broad shell with acute apex; it has little in common with the lectotype designated by them).

Distribution.

Endemic to the Caspian Sea ( Logvinenko and Starobogatov 1969 indicated occurrences for the middle and southern Caspian Sea at depths of 25-80 m, but based on a much wider concept of the species).

Figures

Figure 11. Pyrgulinae. A-C Turricaspia? dimidiata (Eichwald, 1838), RGM 1309787 D, E Turricaspia andrussowi (B. Dybowski & Grochmalicki, 1915), RGM 1309814.