Disc broad, wedge-shaped, wider than long, front broadly convex, sides straight; snout relatively long (8-15% of disc width); eyes very small; mouth slightly arched, floor of mouth with cross row of 10-12 forked, fleshy papillae, teeth with quadrangular bases, low sharp tips; a broad flap between round nostrils and mouth; a row of small thorns along center of back; tail much longer than disc length, with thick base, tapering to a slender point, with one long large serrated venomous spine; tail without a dorsal ridge, with a low ventral fleshy ridge from tail origin to the base of the spine.
Upper surface dark purple to green-blue to black; lower surface dark brown to black.
Size: 163 cm long, 80 cm disc width.
Habitat: pelagic, continental shelf and open ocean, occasionally nearshore.
Depth: 0-250 m.
Probably circumtropical; southern California to Chile, except the Gulf of California, all the oceanic islands.