Syngnathus vesculus, Schwarzhans & Klots & Kovalchuk & Dubikovska & Ryabokon & Kovalenko, 2024

Syngnathus vesculus n. sp.

Figure 6 View FIGURE 6 C-J

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Holotype. NMNHU-P PI 2708 ( Figure 6 View FIGURE 6 C-E), Staryi Zavod , western Ukraine, late Badenian.

Paratypes. 6 otoliths, SMF PO 101.351 , same data as holotype .

Etymology. From vesculus (Latin) = slim, referring to the slender shape of the otolith and the sulcus.

Diagnosis. OL:OH = 1.85–2.25; OL:SuL = 1.5– 1.6. Rostrum and antirostrum short, equally long; excisura small. Sulcus narrow, slightly oscillating; ostium deeper than cauda; OsL:CaL = 1.65–2.0.

Description. Small, elongate, and relatively thin otoliths up to 1.45 mm in length (holotype). OL:OH = 1.85–2.25; OH:OT = 1.9–2.3. The anterior tip of the otolith is blunt, with a short, equally long rostrum and antirostrum and a small excisura inbetween. Dorsal and ventral rims are shallow, highest at their middle, symmetrical. The posterior rim is rounded or blunt. All rims are smooth. The inner face is nearly flat, smooth, with a slightly supramedian positioned, rather short and narrow sulcus; OL:SuL = 1.5–1.6. The sulcus is slightly oscillating, slightly upward shifted in the rear part of the ostium. The latter is distinctly deeper and longer than a shallow cauda and of equal width; OsL:CaL = 1.65–2.0. The dorsal depression and ventral furrow are not discernible. The outer face is moderately to distinctly convex, smooth.

Discussion. In contrast to relatively commonly found articulated fossil skeletons of syngnathids (see for instance Bannikov, 2010), there are no fossil records of syngnathid otoliths. This discrepancy probably has to do with the robust skeleton of these fishes enhancing their fossilization in contrast to their tiny otoliths, which cannot be expected in the typically used 1 mm mesh frame. Therefore, S. vesculus is the first fossil otolith-based record in the group. All otoliths here recorded have been found in mesh frames smaller than 1 mm, that is, 0.5 mm, and most of the specimens are indeed shorter than 1 mm in length except for the holotype. Extant otoliths of syngnathids have been figured in Lombarte et al. (2006) and Nolf (2013). Syngnathus vesculus resembles otoliths of the extant S. acus Linnaeus, 1758 (see Lombarte et al., 2006 and Nolf, 2013 for figures) but differs in the larger size it can attain and the smooth otolith rims.