Genyonemus, Gill, 1861

Bratishko, Andriy, Kovalchuk, Oleksandr & Schwarzhans, Werner, 2017, Bessarabian (Tortonian, Late Miocene) fish otoliths from a transitional freshwater-brackish environment of Mykhailivka, Southern Ukraine, Palaeontologia Electronica 17 (9), pp. 1-13 : 5

Genyonemus ? sp.

Figure 3.5 -8

Material. Two otoliths ( NMNHU-P 33/1485, 1512, Mykhailivka 1).

Description. The elongate otolith is about 5 mm long, but its posterior part is not preserved. The ventral rim is smooth and anteriorly curved. The anterior tip is rounded. The dorsal rim is curved and slightly serrated with a broad median lobe, which is also slightly crenulated.

The inner face is faintly convex. The anterior part of the outer face is slightly concave and ornamented with many short radial furrows, while the posterior part is thickened and slightly convex. The sulcus is shallow with the cauda slightly deeper than the ostium. The ostium is three times wider than the cauda and is widened both dorsally and ventrally. The cauda terminates very close to the anterior rim of the otolith. The cauda is straight, only slightly bent posteriorly when approaching the posteroventral rim of the otolith. The crista superior is distinct.

Comparison. This otolith is very similar to the holotype of “genus aff. Genyonemus ” pertenuis Müller, 1999 from the lower/middle Miocene of Eastern USA ( Müller, 1999). It differs in the narrower cauda and more expressed postostial lobe. Rückert-Ülkümen (1996) described Serranus acuterostratus from Turkey, which may belong to the same genus as the ones from Mykhailivka. Our specimen, however, differs from Genyonemus? acuterostratus ( Rückert-Ülkümen, 1996) in its anterior part being less elongate.

Figures

FIGURE 3. Otoliths from the Sarmatian s.l. of the Mykhailivka 1. 1-4, Morone cf. nobilis (Koken, 1891): NMNHU-P 33/ 1482, inner face (1), ventral view (2); NMNHU-P 33/1483, inner face (3), ventral view (4). 5-8, Genyonemus? sp.: NMNHU-P 33/1485, inner face (5), ventral view (6); NMNHU-P 33/1512, inner face (7), ventral view (8). 9-18, Ponticola dorsorostralis (Weinfurter, 1954): NMNHU-P 33/1486, inner face (9), ventral view (10); NMNHU-P 33/1487, inner face (11), ventral view (12); NMNHU-P 33/1488, inner face (13), ventral view (14); NMNHU-P 33/1489, inner face (15); NMNHU-P 33/1490, inner face (16); NMNHU-P 33/1491, inner face (17); NMNHU-P 33/1492, inner face (18). Scale bars equal 1 mm. 5-10, 17, 18 are mirrored.