rays, belonging to the class Chondrichthyes, are the general names of many kinds of flat-body Chondrichthyes. It is distributed in most water areas of the world, from tropical to near-Arctic waters, from shallow water to deep water below 27 meters. ***9 genera, 3 families. Rays are round or diamond-shaped, with wide pectoral fins, which extend from the snout to the slender tail root; Some species have a pointed snout, which is formed by coracoid cartilage protruding from the skull. The body is monochromatic or patterned, most kinds of ridges have spines or spines, and some tail parts have power generating organs with weak power generating capacity. Rays vary in size: the adult ray is only 5 cm; The giant ray can be as long as 2.5 meters. Rays are harmless and benthic, and are often partially buried in underwater sand. Manta rays are the largest species of manta rays, generally flat [1], wider than long, with a maximum width of 8 meters and a weight of 3 kilograms. The body plate is rhombic, and one end is wide and flat; The snout is wide and flat; The pectoral fin grows like a wing, and there are two prominent head fins differentiated from the pectoral fin in front of the head, which are located on both sides of the head; The tail is as slender as a whip, with a small dorsal fin, and some species have a stinger on the tail; Mouth wide, front or lower; The teeth are thin and numerous, and they are arranged like stones. The upper and lower jaws are toothed, or the upper jaw is toothless; The nostril is just on the side of 4 pictures of two manta rays in front of the mouth, and the water outlet hole is opened in the corner of the mouth; The spray hole is small and triangular, located behind the eye, with a considerable distance from the eye; Branchial foramen is wide; The belt is deeply curved, with a sharp extension in the middle. Viviparous Fossils are found from tertiary to modern times.