Chondrichthyes

Chondrichthyes ( /kɒnˈdrɪkθi.iːz/; from Greek χονδρ- chondr- 'cartilage', ἰχθύς ichthys 'fish') or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, a two-chambered heart, and skeletons made of cartilage rather than bone. The class is divided into two subclasses: Elasmobranchii (sharks, rays and skates) and Holocephali (chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class).

Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates, the extant members of which all fall into Teleostomi.