A revision of the Pontocaspian gastropods of the subfamily Caspiinae (Caenogastropoda: Hydrobiidae) Author Anistratenko, Vitaliy V. 0000-0003-0832-7625 Department of Invertebrate Fauna and Systematics, Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, B. Khmelnytsky Str. 15, 01030 Kiev, Ukraine. Author Neubauer, Thomas A. 0000-0002-1398-9941 Department of Animal Ecology and Systematics, Justus Liebig University, Heinrich-Buff-Ring 26 - 32 IFZ, 35392 Giessen, Germany. tneub @ zo. jlug. de; https: // orcid. org / 0000 - 0002 - 1398 - 9941 & Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, The Netherlands. tneub@zo.jlug.de Author Anistratenko, Olga Yu. 0000-0003-3655-0701 Department of Invertebrate Fauna and Systematics, Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, B. Khmelnytsky Str. 15, 01030 Kiev, Ukraine. & Department of Cainozoic Deposits, Institute of Geological Sciences, National Academy of Sciences of Ukraine, O. Gontchar Str. 55 b, 01054 Kiev, Ukraine. Author Kijashko, Pavel V. 0000-0002-5270-7900 Zoological Institute, Russian Academy of Sciences, Universitetskaya Emb. 1, 199034 Saint Petersburg, Russia. Author Wesselingh, Frank P. 0000-0002-1868-1815 Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, The Netherlands. & Department of Earth Sciences, Utrecht University, Budapestlaan 17, 3584 CD Utrecht, The Netherlands text Zootaxa 2021 2021-02-19 4933 2 151 197 journal article 8059 10.11646/zootaxa.4933.2.1 1a2ba1ca-028f-4b95-8dda-5ddec4e63524 1175-5326 4550146 5D1D20A5-0F44-4AEF-AF5F-A758FC37D076 Laevicaspia derzhavini ( Logvinenko & Starobogatov, 1969 ) comb. n. Fig. 19 f–h Pyrgula ( Ulskia ) derzhavini Logv. et Star. — Logvinenko & Starobogatov 1969: 379 , fig. 367(9). Pyrgula derzhavini Logvinenko et Starobogatov, 1968 — Kantor & Sysoev 2006: 99 , pl. 45, fig. J. ? Ulskia derzhavini ( Logvinenko & Starobogatov, 1969 ) — Wesselingh et al . 2019: 73 . Type material. Kantor & Sysoev (2006: 99) stated that in ZIN no identified material of this species is found. We detected a lot in the ZIN collection of Starobogatov with six specimens and determined as “ Caspia derzhavini ”. Since this material is a single lot that was labelled by Starobogatov himself it is very likely the type material . Type locality. Caspian Sea, probably near Cheleken Peninsula ( Table 1 , locality 21). Other material. None. Remarks. The shells of this species have a very slender elongate shape, and the protoconch ornamentation differs largely of that found in Caspiinae , showing irregular spiral threads on a smooth surface. Shape and protoconch features strongly remind of Laevicaspia ( Neubauer et al . 2018 ) . The small size and the short shell with only about five whorls suggest L. derzhavini is a juvenile Laevicaspia , and it might well be a synonym of a previously described Laevicaspia species. This problem cannot be properly solved from the material available for the species, which is why we consider L. derzhavini as a nomen dubium. Distribution. Middle and South Caspian Sea, 45–81 m ( Logvinenko & Starobogatov 1969 ). Tarasov (1996b) mentioned the species from 311– 870 m .