A large thresher with relatively small eyes, curved, narrow-tipped pectoral fins, a narrow-tipped caudal fin, and a conspicuous white patch over the pectoral fin bases (Ref. 5578). Second dorsal origin well behind the rear tip of the pelvic fin (Ref. 559). Upper lobe of caudal fin very long and strap-like, about as long as or longer than length of rest of shark; lower lobe short but well developed (Ref. 13570). Brown, grey, blue-grey, or blackish on back and underside of snout, lighter on sides and abruptly white below; a white area extends from the abdomen over the pectoral-fin bases; pectoral-, pelvic-, and dorsal fins blackish, white dots sometimes present on pectoral-, pelvic-, and caudal- fin tips (Ref. 13570).