A review of the systematics of western North Pacific angel sharks, genus Squatina, with redescriptions of Squatina formosa, S. japonica, and S. nebulosa (Chondrichthyes: Squatiniformes, Squatinidae). Author Jonathan H. Walsh Author David A. Ebert text Zootaxa 2007 1551 31 47 http://www.zoobank.org/urn:lsid:zoobank.org:pub:DD00E8E3-2C28-41A8-A401-E0D00DA325B9 journal article z01551p031 DD00E8E3-2C28-41A8-A401-E0D00DA325B9 Genus Squatina Dumeril , 1806 Squatina Dumeril , 1806 : 102, 342. Type Squalus squatina Linneaus 1758 , by subsequent designation. Rhina Rafinesque 1810 : 4. Type Squalus squatina Linneaus 1758 , type by monotypy. Definition. Broad, flattened body with large bat-like pectoral fins. Mouth terminal, broadly arched with ornate nasal flaps and highly protrusible jaws. Spiracles large, without valves. Pectoral fins not fused to head, origin opposite gill openings. Anterior extent of pectorals triangular and covering gill openings. Five pairs of gill openings positioned between pectoral origin and base of the head. Trunk compressed dorsal-ventrally. Two dorsal fins, spineless, originating behind pelvic fin insertion on the precaudal. Anal fin absent. Furrow on ventral from dorsal origin to caudal peduncle. Caudal fin hypocercal. Total length, depending on species, generally between 1-2 m.