Ponticola dorsorostralis ( Weinfurter, 1954 )

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 : 5-7

Ponticola dorsorostralis ( Weinfurter, 1954)

Figure 3.9 -18

1954 Gobius dorsorostralis nov. spec.; Weinfurter, pl. 6, figs. 49-50.

1954 Gobius dorsorostralis sculpta n. sp., n. ssp.; Weinfurter, pl. 6, figs. 51-52.

1992 Gobius sp. , aff. Gobius dorsorostralis Weinfurter, 1954 ; Brzobohatý, pl. 1, fig. 2.

2010 Gobius dorsorostralis Weinfurter, 1954 ; Schwarzhans, pl. 103, figs. 2-4.

2013 Gobius dorsorostralis Weinfurter, 1954 ; Nolf, pl. 320.

2014 Gobius dorsorostralis Weinfurter, 1954 ; Schwarzhans, pl. 8, figs. 1-2.

2014 Gobius aff. dorsorostralis Weinfurter, 1954 ; Schwarzhans, pl. 8, fig. 3.

Material. Ten otoliths ( NMNHU-P 33/1486-1495, Mykhailivka 1).

Description. The rectangular otoliths are moderately elongate. Sizes range from 3 to 5 mm in length. OL:OH = 1.35-1.5. The anterior and posterior rims are inclined, slightly rounded, or straight. They have pronounced anterodorsal and posteroventral angles. The dorsal rim is slightly curved and intensely but irregularly undulating or sometimes deeply crenulated. The otoliths have a well-developed rounded (pointed in juveniles) posterodorsal projection. The ventral rim is nearly flat, and smooth with a well-expressed slightly pointed anteroventral projection. The otoliths are thin. The inner face is slightly convex. The sulcus is sole-shaped with a gently pointed tip of the ostium. The latter is wider and longer than the cauda, although the distinction is fluent. There is no subcaudal iugum. The ventral furrow is well-expressed. Adult specimens, have a distinct dorsal depression. The outer face is slightly concave with some ornamentation and protuberances.

Comparison. This species is similar to several extant species of Ponticola in otolith shape and the lack of a subcaudal iugum (see Vasilieva et al., 2016). It is best recognized by the intensely ornamented dorsal rim and the moderate index of OL:OH.

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.