Valvata piscinalis ( Mueller , 1774)

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

Valvata piscinalis ( Mueller, 1774)

Fig. 14A-D

*1774 Nerita piscinalis - Müller: 172.

1928 Valvata (Cincinna) piscinalis piscinalis ( Müller) - Wenz: 2443-2445.

2002 Valvata (Cincinna) piscinalis piscinalis (O. F. Müller 1774) - Glöer: 190-191, textfig. 2019.

2012 Valvata piscinalis ( Müller, 1774) - Welter-Schultes: 44, unnumbered textfig.

2019 Valvata (Cincinna) piscinalis piscinalis (O. F. Müller, 1774) - Glöer: 204-205, textfig. 256.

Material.

1 specimen (RGM 962694) from sample 3.

Dimensions.

6.25 × 6.15 mm.

Remarks.

This well-known extant species is a typical representative of Quaternary freshwater mollusk faunas. It is known for its morphological variability, especially concerning the outline shape, ranging from nearly conical to broadly ovoid, being a result of an inflated penultimate whorl ( Glöer 2002, 2019; Welter-Schultes 2012). The apex is depressed, the aperture is nearly circular and the umbilicus is wide. All these features match well the Turkish specimen, which also shows an expanded penultimate whorl. Only, it is slightly larger than the average extant members of the species (up to 4.5 mm high and 5 mm broad; Glöer 2019).

The material also resembles the depressed morphotype of the extant Valvata lilljeborgi Westerlund, 1897 in terms of the inflated penultimate whorl. That species comprises a broader range of morphologies, also including unusually high-spired forms ( Vinarski et al. 2013). The species is today restricted to cold-temperate regions of the Baltic Sea Basin, the Dnieper Basin, and Western Siberia ( Vinarski et al. 2013; Glöer 2019). Considering the above, we consider an identification with the more common V. piscinalis more likely.

Distribution.

Today present throughout the Palearctic, also introduced to North America ( Welter-Schultes 2012; Glöer 2019). Common in Upper Miocene to Pleistocene deposits across Europe (Wenz 1923).

Figures

Figure 14. Valvatidae of the Kolankaya I fauna. A-D. Valvata piscinalis (Mueller, 1774), RGM 962694, sample 3. E-H, U, V. Valvata sp. 1, RGM 1365352, sample 1. I-L, W. Valvata sp. 1, RGM 962695, sample 2. M-P. Valvata gregaria Bukowski, 1896, lectotype (designated by Willmann 1981), IGUW 1895 XII / 25, Skiadhi Monastery, Rhodes, Greece, Istrios Formation (Pliocene). Q-T. Valvata gregaria Bukowski, 1896, paralectotype, IGUW 1895 XII / 26, same locality and stratum. Scale bars: 1 mm (A-T); 100 μm (U-W).