Coryphopterus xenosus, Schwarzhans & Aguilera, 2024

Coryphopterus xenosus n. sp.

Figure 39r–t View Fig

Holotype NMB P15808 View Materials ( Fig. 39r View Fig ), Zanclean , Cubagua FM, Venezuela, PPP 2556 .

Paratypes 2 specimens: 1 specimen same data as holotype ( NMB P15809 View Materials ) ; 1 specimen Messinian , Manzanilla FM , Montserrat Member , Trinidad, PPP 2673 ( NMB P15810 View Materials ) .

Referred specimens 1 specimen Zanclean, Cubagua FM , Venezuela, PPP 25565 .

Etymology From xenos (Greek) = foreign, referring to the unusual pattern of the otolith.

Diagnosis Otolith size up to 1.35 mm in length. OL:OH = 1.15. Otolith skewed rectangular with relatively high predorsal angle and slightly protruding postdorsal projection. Preventral projection blunt, short. Sulcus short and narrow, with moderately developed low ostial lobe and narrow cauda; OL:SuL = 1.9; sulcus inclination angle 12–14°. No subcaudal iugum. Ventral furrow distinct, regularly curved.

Description Otolith size up to 1.35 mm in length (holotype). OH:OT = 2.5–2.8. Otolith skewed rectangular; dorsal with straight, downward inclined predorsal part, shallow postdorsal angle and high, distinct, rounded predorsal angle; postdorsal projection rounded, slightly protruding beyond broadly rounded postventral angle. Anterior rim nearly vertical, with weak concavity at level of ostial tip. Posterior rim slightly inclined towards ventral, with weak concavity at level of tip of cauda. Ventral rim straight, horizontal, with rounded slightly protruding preventral projection. All rims smooth.

Inner face slightly convex. Sulcus relatively short, narrow, distinctly deepened, its ostial and caudal tips tapering; ostial lobe moderately developed; sulcus inclination angle 12–14°; OL:SuL= 1.9. No subcaudal iugum but sometimes weak indications ( Fig. 39s, t View Fig ) similar to certain extant otoliths of the genus. Dorsal depression relatively distinct, narrow, short, with broad crista inferior towards sulcus; ventral furrow distinct, close and to ventral rim of otolith. Outer face distinctly convex, much stronger than inner face, smooth.

Discussion Coryphopterus xenosus differs from the otoliths of the known extant species in the more rectangular otolith shape and the relatively thick habitus of the otolith. Also untypical is the high positioned predorsal angle. It is possible that this species rather represents an extinct genus but we would consider such allocation premature at the moment considering the limited knowledge of fossil Coryphopterus today.