Blackchin guitarfish

Vertebrae: 68-73. This large to very large species has a plain beige to brownish wedge-shaped disc; long and rather broad triangular snout with a broadly rounded rostral cartilage at its tip and wide oblique nostrils with a narrow anterior opening; disc thickened centrally, length 1.2-1.3 times its width, anterior margins slightly undulate, often weakly concave before broadly rounded outer corner; snout moderately acute, its angle 59-63°, tip narrowly rounded not extended forward as a distinct lobe; large orbit, length 5-6 times in preorbital length, 1.5-2 in interorbital space; rostral ridges are narrowly separated posteriorly and almost joined anteriorly; 2 fleshy spiracular folds, with innermost fold smaller; upper jaw with 62-72 tooth rows; large and oblique nostrils, its length 1.4 in internasal width, ca 81 nasal lamellae, anterior nasal flaps are confined to anterior margin of nostril; rough skin covered entirely with small denticles; well-developed thorns, usually along edge of rostral cartilage and small patches around orbits and above spiracles; each shoulders with 1-3 thorns that persist in adults, a median row of enlarged thorns extending from nape to first dorsal fin, a few thorns between dorsal fin; long tail ca 1.5 times its disc length; dorsal fins are large and widely spaced, ca. 2.1 times base length of first dorsal fin, apices narrowly rounded; pectoral fin radials 68-73; 204-212 total vertebrae (Ref. 114953).