Gobulus limonensis, Schwarzhans & Aguilera, 2024

Gobulus limonensis n. sp.

Figure 34f–g View Fig

Holotype NMB P15767 View Materials ( Fig. 34f View Fig ), Gelasian , Moin FM, Atlantic Costa Rica, PPP 1773 .

Paratype 1 specimen Gelasian , Moin FM , Atlantic Costa Rica, PPP 1772 ( NMB P15768 View Materials ) .

Etymology Named after the province Limón, Costa Rica, where the specimens were collected.

Diagnosis Otolith size up to 2.5 mm in length. OL:OH = 1.2–1.25. Otolith moderately elongate but with depressed predorsal section. Postdorsal projection and postventral angle equally protruding with broad concavity of posterior rim in between; ventral rim curved, horizontal. Sulcus moderately long, wide, with very low ostial lobe; OL:SuL = 1.85–1.95; sulcus inclination angle 5–6°. No subcaudal iugum. Ventral furrow regularly curved.

Description Otolith size up to 2.5 mm in length (holotype). OH:OT = 2.8–3.2. Otolith moderately elongate; dorsal rim shallow, predorsal section depressed, regularly declining towards low predorsal angle; postdorsal angle highest point, broadly rounded. Postdorsal projection distinct, moderately protruding, about as strongly as projecting postventral angle; posterior rim with broad, distinct concavity between postdorsal and postventral projections. Anterior rim short, nearly vertical. Ventral rim curved, horizontal. All rims smooth.

Inner face moderately convex in both directions; area around sulcus slightly bulged. Sulcus relatively short but wide, deepened, with very low ostial lobe, and cauda about equally wide as ostium; sulcus inclination angle 5–6°; OL:SuL= 1.85–1.95. No subcaudal iugum. Dorsal depression indistinct, joint to distinct ventral furrow around sulcus; ventral furrow half-moon shaped, close to ventral rim of otolith only at central part. Outer face nearly flat, smooth.

Discussion Otoliths of Gobulus limonensis are exceptionally large for otoliths of the Nes clade or the genus Gobulus . An otolith of the extant G. crescentalis of 61 mm SL, which is the largest recorded specimen of the species ( Robertson & Allen, 2015) and represents the largest extant species of the genus, is 1.8 mm in length. Te fishes from which the fossil G. limonensis otoliths are described may have surpassed 80 mm SL. In a redescription of the only extant Atlantic species, Gobulus myersi Ginsburg, 1939 , Hastings (1983) found no specimen larger than 29.3 mm SL among all known specimens. Te size correlation therefore rules out G. limonensis being synonymous with the extant G. myersi , even though no otoliths are known from the latter.