Disc rhomboidal, very robust centrally, quadrangular, width 1.1 to 1.2 times length; pectoral-fin apex broadly rounded; snout very broad, tip feebly pointed; anterior margin straight to slightly convex. Tail very long (about twice disc width), base rather narrow, almost cylindrical in cross-section; whip-like behind sting; mostly with single sting. Eyes small, length of eye and spiracle about 2.6 in preorbital snout length; interorbital space broad. Mouth moderately small, 4 papillae on floor (central pair enlarged, laterals minute); labial furrows and corrugations prominent. Internasal flap skirt-shaped, short, and very broad, not papillate, marginal fringe very fine; nostrils long, very narrow; lower jaw slightly concave near symphysis. Pelvic fins small, relatively slender. No cutaneous folds. Denticles of adults rounded, dense, extending from well before eye, over central disc, and mostly covering entire tail; no enlarged thorns on midline; small, sharp, upright thorns on tail beyond sting. In juveniles, disc surface and tail mostly smooth, or with low, flat, widely spaced, heart-shaped denticles extending from interorbital space posteriorly over centre of disc and onto midline of tail. Max length : 183 cm. max. published weight: 18.5 kg.