Esperiana esperi ( Ferussac , 1823)

Neubauer, Thomas A. & Wesselingh, Frank P., 2023, The Early Pleistocene freshwater mollusks of the Denizli Basin (Turkey): a new long-lived lake fauna at the crossroads of Pontocaspian and Aegean-Anatolian realms, Zitteliana 97, pp. 53-88 : 53

Esperiana esperi ( Ferussac, 1823)

Fig. 5A-F

*1823 Melanopsis Esperi , nobis - Férussac: 160.

1974a Melanopsis (Melanopsis) cf. bergeroni Stefanescu - Taner: 116, pl. 9, figs 16-21.

2018 Esperiana esperi ( Férussac, 1823) - Neubauer et al.: 89. fig. 17N.

2012 Esperiana esperi ( Férussac, 1823) - Welter-Schultes: 35, unnumbered textfig.

2019 Esperiana (Esperiana) esperi (A. Férussac, 1823) - Glöer: 83, textfig. 83.

Material.

Sample 1: 3 specimens (RGM 962691-962693), 10 specimens (SNSB-BSPG 2023 XII 4), ca. 300 specimens (RGM 1310843); sample 3: 13 specimens (RGM 1310844), 1 specimen (RGM 1365348).

Dimensions.

16.25 × 7.78 mm (RGM 962691; Fig. 5A-C ), 14.44 × 7.47 mm (RGM 962692; Fig. 5D, E ).

Remarks.

The present material matches well the extant Esperiana esperi concerning the elongate, smooth shell with adpressed whorls, lanceolate aperture with thickened inner lip and the slight concavity between base of the last whorl and base of the aperture ( Welter-Schultes 2012; Glöer 2019). Even the color pattern, consisting of dissected zigzag lines to a chess-like arrangement of orange spots, and the corroded apex are typical of the modern species.

Shape, apertural characteristics and color pattern are also found in the Plio-Pleistocene species Melanopsis bergeroni Stefanescu, 1896 from the Dacian Basin (Romania) ( Stefanescu 1896; Pană et al. 1981; Pană 2003). The same is true for Melanopsis esperioides Stefanescu, 1896 from the same region, which seems to be only slightly more slender and larger on average than M. bergeroni ( Stefanescu 1896). It might well be that both species range within the morphological variability of E. esperi , but a final verdict on their status requires comparison with topotypic material from the Dacian Basin. In case of synonymy, the subgenus Melanopsis (Calodiona) Stefanescu, 1896, of which M. bergeroni is the type species, would become a synonym of Esperiana .

The specimens from the Denizli Basin studied by Taner (1974a) and identified as M. cf. bergeroni falls well into the range of E. esperi and considered conspecific herein.

Distribution.

Today in central to southeastern Europe (western Black Sea region to Hungary, Slovakia, Austria, and Slovenia) and northwestern Anatolia ( Welter-Schultes 2012; Glöer 2019). Also found in Pleistocene strata of the North Caspian Basin ( Neubauer et al. 2018).

Superfamily Truncatelloidea Gray, 1840

Family Hydrobiidae Stimpson, 1865

Subfamily Caspiinae B. Dybowski, 1913

Figures

Figure 5. Melanopsidae of the Kolankaya I fauna. A-C. Esperiana esperi (Ferussac, 1823), RGM 962691, sample 1. D, E. E. esperi, RGM 962692, sample 1. F. E. esperi, RGM 962693, sample 1. Scale bars: 5 mm.