Rhynchoconger carnevalei, Schwarzhans, 2023

Rhynchoconger carnevalei n. sp.

Figure 11a–c View Fig

1978a Gnathophis sp. —Schwarzhans: Figs. 55, 139.

Holotype SMF PO 101.191 ( Fig. 11b View Fig ), Agrigento , below Rupe Athenae, Sicily, Italy, Zanclean.

Paratype Two specimens: one specimen MGPT-PU 130452 , Borelli , Piedmont, Italy, late Tortonian ; one specimen SMF PO 101.336 , Orciano near Pisa, Tuscany, Italy, Zanclean .

Etymology In honor of Giorgio Carnevale, Torino, Italy, for his many contributions to the understanding of fossil bony fishes.

Diagnosis OL:OH = 1.8–2.1; OH:OT = 2.5–3.1. Dorsal rim anteriorly depressed and generally low; ventral rim shallow, regularly curved. Ostium closely approaching anterior rim of otolith.

Description Slender, large, elegant otoliths reaching sizes of 17 mm in length (holotype). OL:OH = 1.8–2.1, increasing with size; OH:OT = 2.5–3.1, decreasing with size. Dorsal rim shallow, anteriorly depressed and irregular, highest behind middle of otolith. Ventral rim shallow, smooth and very regularly curved. Anterior tip rounded, posterior tip slightly tapering.

Inner face convex, with a long, nearly horizontal and relatively narrow sulcus. Ostium marked against cauda at ventral sulcus rim by slight indentation, its anterior tip reaching close to anterior rim of otolith. Ostial channel narrow, short, positioned perpendicular on rear part of ostium. Cauda narrow, straight. Single colliculum contiguous from ostium, including ostial channel and cauda. OL:SuL = 1.6–1.7; CaL:OsL = 1.3–1.4. Dorsal depression narrow, relatively shallow and with indistinct margins; no ventral furrow. Outer face smooth, flat or with moderate central umbo.

Discussion Te presence of a second species of Rhynchoconger in the young Neogene of the Mediterranean was already recognized by Schwarzhans (1978a), who refrained from describing a new species based on a single large specimen. With the finding of two additional specimens of smaller and intermediate size, it is now clear that the morphological characteristics are stable through ontogeny. Te species is much rarer than R. pantanellii and differs mainly in being distinctly more elongate (OL:OH = 1.8–2.1 vs. <1.6), the depressed predorsal rim and the ostium approaching the anterior rim of the otolith more closely than in R. pantanellii . Its stratigraphic range in the Mediterranean reaches from the late Tortonian to the Zanclean. It is described here because it is considered relevant for the faunal evaluation discussed later.