Elasmobranchii Subclass of shark-like fish. They have 5–7 gill slits, fairly rigid fins, placoid scales, a spiracular opening behind the jaws, numerous teeth, and claspers on the ventral fins of the male. Elasmobranchs have a cartilaginous skeleton and their fossil record consists mainly of teeth and fin rays. Well-known fossil genera include Cladoselache (Devonian), and Ctenacanthus (Upper Devonian to Lower Permian). See CARTILAGE; and CARTILAGINOUS FISH.

Elasmobranchii (class Chondrichthyes) A subclass of shark-like fish that have five–seven gill slits, fairly rigid fins, placoid scales, a spiracular opening behind the jaws, numerous teeth, and claspers on the ventral fins of the male. Modern elasmobranchs have a cartilaginous skeleton. Apart from modern sharks and rays, the subclass also includes many fossil species.

Elasmobranchii See Chondrichthyes.