Rhinopteridae
by J. D. McEachran and C. Capape
Medium to large rays (disc width to 2.1 m), the disc lozenge-shaped, much wider than long; head elevated from disc, with eyes and spiracles on side; tail distinct from disc, much longer than disc length, with one or several serrated spines on top near base. Mouth underneath, without papillae on floor; teeth tesselate, fused into grinding plates, generally in 7 or more rows. Dorsal fin small, in front of spine; pectoral fins reaching forward, each forming a distinct but separate lobe below tip of snout, the finrays not continued above corner of mouth; no caudal fin. Upper surfaces naked or with thornlets.
Semipelagic in tropical to warm temperate coastal waters (but absent from islands of western Pacific); moderately common in tropical inshore waters, gregarious, often forming large groups swimming near the surface; seldom marketed, but destructive of commercial oyster and clam beds. Feeding on bottom-living molluscs, crustaceans and fishes. Ovoviviparous; females contain 2-6 embryos, with a gestation period of up to one year.
Genera 1.
Recent revisions: on a regional basis only by Fowler (1941), Bigelow and Schroeder (1953).