Sphaerium rivicola Lamarck, 1818

Frolov, Pavel D., Danukalova, Guzel A. & Osipova, Eugenia M., 2018, Late Miocene molluscs of the Morskaya 2 site (Azov Sea region, Russia), Palaeontologia Electronica (a 20) 23 (1), pp. 1-32 : 18-19

Sphaerium rivicola Lamarck, 1818

Figure 5.7

1818 Cyclas rivicola Lamarсk, p. 558, pl. 5.

1952 Sphaerium rivicola (Lamarсk); Zhadin, p.

319, fig. 285.

1955 Sphaerium rivicola (Lamarсk); Danilovskiy, p. 121, pl. 15, figs. 458, 459.

1960 Sphaerium rivicola (Lamarсk); Kirillina, p.

152, pl. 13, figs. 172-173, 174, 175, 176.

1964 Sphaerium rivicola (Lamarсk); Ložek, p.

323, fig. 83.

1977 Sphaerium rivicola (Lamarсk); Starobogatov, p. 137, fig. 291.

1998 Sphaerium rivicola (Lamarсk); Gittenberger, Janssen, Kuijper, Kuiper, Meijer, Velde and Vries, p. 224, figs. 521, 607-608.

2007 Sphaerium rivicola (Lamarсk); Sanko, p.

37, fig. 22.

Material. 8 specimens from layer 3 (4 left valves, 4

right valves).

Description. Elongated-rounded shell (HS is 8.0-

10.8 mm, 9.01 in average; LS is 10.4-14.0 mm,

11.8 in average; Con. is 2.7-4.4 mm, 3.2 in average) moderately convex, almost equilateral, the posterior margin wider and slightly longer than the anterior one. Umbo is almost in the middle of the valve, wide, convex but not swollen, slightly protruding above the posterior margin. Dorsal edge is narrow. There are two cardinal teeth in the left valve, the posterior is short and thin, and the anterior is coarse, high, and triangular at the base. Between the two teeth is a wide triangular deepening. Lateral teeth are single. There are two cardinal teeth in the right valve, the posterior one is triangular, with a deep groove at the top, and the anterior is thin and slightly curved. Lateral teeth are doubled. Upper teeth are thinner, lower, and shorter than lower teeth. The deepening between them is short, narrow, and deep.

Region of distribution and age. Late Pliocene – Present. European part of Russia and Europe (Gittenberger et al., 1998). Late Miocene of the the northeastern Azov Sea region.

Figures

FIGURE 5. Assemblage of the Maeotian freshwater molluscs (layer 3). 1, Borysthenia cf. pronaticina (Lindholm, 1932). 2-3, Lithoglyphus acutus Cobălcescu, 1883; 2, smooth shell; 3, shell with keel. 4, Viviparus cf. karaganicus Volkova, 1939. 5, Viviparus cf. maeoticus (Bogachev and Shishkina, 1919). 6, Lymnaea sp. 7, Sphaerium rivicola Lamarck, 1818. 8, Gyraulus cf. acronicus (Ferrussac, 1807). 9-10, Bithyniidae, opercula.