Clathrocaspia valkanovi ( Golikov & Starobogatov, 1966 )

Anistratenko, Vitaliy V., Neubauer, Thomas A., Anistratenko, Olga Yu., Kijashko, Pavel V. & Wesselingh, Frank P., 2021, A revision of the Pontocaspian gastropods of the subfamily Caspiinae (Caenogastropoda: Hydrobiidae), Zootaxa 4933 (2), pp. 151-197 : 185-186

† Clathrocaspia valkanovi ( Golikov & Starobogatov, 1966)

Fig. 18g, h

P. [yrgula] (Caspia) baeri [sic] valkanovi subsp. n. — Golikov & Starobogatov 1966: 354–355, fig. 1(9).

Caspia (Clathrocaspia) valkanovi valkanovi (Gol. et St.) — Alexenko & Starobogatov 1987: 32, 37.

Caspia valkanovi ( Golikov et Starobogatov, 1966) — Kantor & Sysoev 2006: 88, pl. 41, fig. N.

Caspia valkanovi ( Golikov & Starobogatov, 1966) — Wesselingh et al. 2019: 68–69 .

Type material. Holotype only ( ZIN 4367 /1).

Type locality. Southern shore of Crimea, from phaseoline silts ( Table 1 , locality 28), probably reworked from Neoeuxinian (Late Pleistocene) strata (compare C. knipowitschii aluschtensis ) .

Remarks. Originally this taxon was described ( Golikov & Starobogatov 1966) as the Black Sea subspecies of Caspia baerii , but later Alexenko & Starobogatov (1987) considered it a separate species and so restricted C. baerii to the Caspian Sea.

Records of C. valkanovi are known off the southern Crimean coast as (sub)fossil shells only. The holotype is poorly preserved and does not allow a proper assessment of identity and status. The general shape and size are indicative of the genus Clathrocaspia and traces of the reticulate sculpture can be seen under high magnification. The shell resembles closely the holotype of the subfossil subspecies C. knipowitschii aluschtensis retrieved from the same deposits ( Fig. 13e ), and both might be synonyms.

Furthermore, we are not entirely certain as to the stratigraphic age of the stratigraphic origin of this species. The phaseoline silt is a marine Holocene unit, which may contain reworked Late Pleistocene Neoeuxinian species ( Wesselingh et al. 2019). Given the uncertainty related to the species’ identity and age, we treat this taxon as a nomen dubium.

Distribution. Endemic to the Black Sea Basin.

Figures

FIGURE 13. Clathrocaspia knipowitschii (Makarov, 1938) from the Black Sea Basin. (a, b) Neotype, locality 30b (IZAN 522/1). (c, d) Specimen from locality 30b (IZAN 522/2). (e) C. knipowitschii aluschtensis (Golikov & Starobogatov, 1966), holotype, locality 29 (ZIN 4438/1). (f) Holotype of Pyrgula makarovi, locality 31 (ZIN 4492/1). (g, l, u) Specimen from Holocene deposits, locality 32 (IZAN, no number). (h, m) Specimen from same locality (IZAN, no number). (i, n) Paratype of C. brotzkajae from same locality (IZAN, no number). (j, k) Specimen from locality 30c (UGSB 25234). (o, s, t) Specimen identified as C. makarovi by Anistratenko (2013) from locality 30c (UGSB 25236). (p–r) Specimen from locality 30c (UGSB 25235). Scale bars = 1 mm (a–j, l–o), 500 μm (k), 100 μm (p–t), 50 μm (u).

FIGURE 18. Doubtful species. (a, b) Clathrocaspia sp., labelled as “Caspia microcingulifera, holotype”, locality 6 (ZIN, no number). (c–f) Clathrocaspia sp., labelled as “Caspia microcingulifera, paratype”, locality 9 (ZIN, no number). (g, h) Clathrocaspia valkanovi, holotype, locality 28 (ZIN 4367/1). (i) Clathrocaspia stanislavi, reconstruction of the holotype (after Alexenko and Starobogatov 1987), locality 30a. (j, k) Paratype of C. stanislavi, locality 30d (NMNH NASU, IKOFZ-It-167). (l) C. stanislavi, locality 30a (det. T.L. Alexenko; UGSB 25237). (m) C. stanislavi from Holocene deposits, locality 32 (IZAN, no number). Scale bars = 1 mm (a–d, g–m), 100 μm (e, f).