Pinichthys shirvanensis Bannikov, 2021

Pinichthys shirvanensis Bannikov, 2021

Figure 1 A View Fig

2021 Pinichthys shirvanensis Bannikov – Bannikov : 672, Figs. 1 View Fig –3.

Material : Shirvanskaya village , 44.368442°N, 39.796874°E, Pshekha River , Krasnodar Region, Russia, Tarkhanian, Langhian, Middle Miocene. Fish specimen: PIN 5599 View Materials GoogleMaps / 12; extracted otolith: SMF PO 101.357 .

Diagnosis (otolith): Tin, oval otolith; OL:OH = 1.7; OH:OT = 4.4. Dorsal rim regularly curved without postdorsal angle. Sulcus long, nearly horizontal median axially positioned. Cauda longer and narrower than ostium, slightly flexed posteriorly and slightly dorsally widened at flexure. Ventral field without ventral furrow.

Description (otolith): Small, thin, oval-shaped otolith of about 2 mm in length. Dorsal rim gently curving, highest anterior of its middle, irregularly undulating; postdorsal region slanted, without postdorsal angle. Ventral rim relatively shallow, regularly curving, smooth. Rostrum massive, long, with rounded albeit slightly damaged tip, about 18% of OL. Antirostrum and excisura weak. Posterior tip rounded, somewhat tapering.

Inner face mildly convex, with narrow, long, moderately deepened, horizontal axially positioned sulcus. OL:SuL = 1.1. Ostium moderately widened, much shorter than cauda. CaL:OsL = 1.4. Cauda long, slightly flexed toward tip and slightly dorsally widened at flexure, terminating close to posterior tip of otolith. Dorsal depression narrow, indistinct; dorsal field with few faint and short radial furrows. Ventral field smooth, without ventral furrow. Outer face flat, almost smooth.

Discussion: Stromateoid otoliths are often characterized by a thin, relatively flat appearance combined with a relatively narrow heterosulcoid sulcus pattern. Te specimen from which the otolith has been extracted is relatively small ( 6.9 cm TL) and the otolith is 1.9 mm in length. Even though rather small, the otoliths of Pinichthys are no exception and the otolith found in situ shows sufficient diagnostic valuable features. Bannikov (2021) compared Pinichthys with the extant stromateid genera and found Pampus Bonaparte, 1834 as putatively related. Te otolith of Pinichthys shirvanensis differs from extant Pampus otoliths (see Lombarte et al., 2006 for figures) in the dorsally widened posterior tip of the cauda (vs. tapering). Tree otolith-based taxa have been described in the past as allocated to Pampus : Pampus pampauensis Schwarzhans, 2010 from the Late Miocene of northern Germany ( Fig. 1D, E View Fig ); P. steurbauti Schwarzhans, 1994 from the late Oligocene to early Middle Miocene of the North Sea Basin ( Fig. 1B, C View Fig ); and P. uedemensis Schwarzhans, 2010 from the Late Miocene of northern Germany ( Fig. 1F View Fig ). Of these, P. steurbauti shows the dorsal widening of the posterior part of the cauda, and the species is therefore relocated to Pinichthys . Pampus pampauensis and P. uedemensis remain within Pampus .

Te otolith of Pinichthys shirvanensis differs from the earlier P. steurbauti in the slanted, low postdorsal region (vs. distinct, rounded postdorsal angle) and the much lower degree of crenulation of the otolith rims, which is intense in P. steurbauti . Bannikov (2021) listed three species of Pinichthys ( P. fractus Bannikov, 1985 , P. pulcher Bannikov, 1988 and P. shirvanensis ) from the early Oligocene to the Middle Miocene, all from the Paratethys, but one that may have also occurred in the North Sea Basin during the early Oligocene. Tis distribution makes it seem unlikely that the otolith-based P. steurbauti would represent the same species as any of the skeleton-based taxa.