Magnogobius grandis, Schwarzhans & Aguilera, 2024

Magnogobius grandis n. sp.

Figure 26h–o View Fig

1992 Gobiidae sp. 1—Nolf & Stringer: pl. 17, Fig. 12 View Fig .

Holotype NMB P386 View Materials ( Fig. 26h View Fig ), Tortonian , Cercado FM, Dominican Republic, NMB 16915 View Materials .

Paratypes 11 specimens: 8 specimens Tortonian: 7 specimens Cercado FM , Dominican Republic; 2 specimens NMB 16918 View Materials ( NMB P15632 View Materials ) ; 2 specimens, NMB 16916 View Materials ( NMB P403 View Materials ) ; 1 specimen NMB 16923 View Materials ( NMB P405 View Materials ) ; 2 specimens NMB 15903 View Materials ( NMB P389 View Materials ) ; 1 specimen Tuira FM , Pacific Panama, Darien, PPP 1163 ( NMB P15638 View Materials ) . 2 specimen Zanclean, Cayo Agua FM , Atlantic Panama, 1 specimen PPP 2222 ( NMB P15633 View Materials ) , 1 specimen PPP 1188 ( NMB P 15637 View Materials ) . 1 specimen Piacenzian, Río Banano FM , Atlantic Costa Rica, PPP 1732 ( NMB P15636 View Materials ) .

Referred specimen 22 specimens: 6 specimens Tortonian : 3 specimens Tuira FM , Pacific Panama, Darien , 1 specimen PPP 1627 , 1 specimen PPP 1154 , 1 specimen PPP 1164 ; 2 specimens Cercado FM , Dominican Republic, NMB 16923 View Materials . 12 specimens Zanclean, Atlantic Panama : 1 specimen Shark Hole FM, PPP 2219 ; 11 specimens Cayo Agua FM , 6 specimens PPP 1276 , 5 specimens, PPP 1188 . 3 specimens Piacenzian, Río Banano FM , Atlantic Costa Rica, 1 specimen PPP 676 , 2 specimens PPP 1732 . 1 specimen Gelasian, Bastimentos FM , Ground Creek Unit, Atlantic Panama, PPP 1252 .

Etymology From grandis (Latin) large, referring to the large size of the otoliths.

Diagnosis Otolith size up to 3.3 mm in length. OL:OH = 0.83–0.92. Otolith shape high-bodied; dorsal rim regularly curved, crenulated, with rounded postdorsal angle and slight postdorsal projection; predorsal angle slightly projecting. Inner face slightly convex. Sulcus long, wide, with strong ostial lobe and deepened cauda; OL:SuL = 1.35–1.5; sulcus inclination angle 15–20°. Subcaudal iugum long, narrow, distinct. Dorsal depression small, cup-shaped, only above central part of sulcus and close to sulcus.

Description Otolith size up to 3.3 mm in length (holotype 2.9 mm). OH:OT = 3.4–3.7. Otolith shape high-bodied with regularly curved dorsal rim highest at its postdorsal angle and usually crenulated. Predorsal angle rounded, often slightly projecting; postdorsal projection blunt or rounded, slightly projecting. Anterior and posterior rims vertical to slightly inclined towards ventral; posterior rim usually straight. Ventral rim straight to slightly bent, horizontal. Preventral angle recessed, postventral angle rounded. All rims crenulated to various extents.

Inner face slightly convex, particularly in horizontal direction. Sulcus long, wide, with strong, often sharp ostial lobe; cauda straight, with rounded tip, slightly upward bent and slightly deepened; sulcus inclination angle 15–20°; OL:SuL = 1.35–1.5. Subcaudal iugum long, narrow, distinct. Dorsal depression small, cup-shaped, only above central part of sulcus; separated from sulcus only by narrow crista superior. Ventral furrow distinct, moderately close to ventral rim of otolith, anteriorly terminating below tip of ostium. Outer face convex, intensely ornamented.

Discussion Magnogobius grandis differs from M. costaricensis in the larger size the otoliths can attain, the larger sulcus with the more strongly developed ostial lobe, the more evenly curved and crenulated dorsal rim, the strongly ornamented outer face and the more steeply inclined sulcus (15–20° vs 12–17°). Both species occur parallel in a number of locations.