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Latest Silurian to Present | image = White shark.jpg | image_width = 250px | image_caption = Great white shark, ''Carcharodon carcharias'' | regnum = Animalia | phylum = Chordata | subphylum = Vertebrata | infraphylum = Gnathostomata | classis = Chondrichthyes | classis_authority = Huxley, 1880 | subdivision_ranks = Subclasses | subdivision = Elasmobranchii Holocephali }} Chondrichthyes (; from Greek χονδρ- ''chondr-'' 'cartilage', ἰχθύς ''ichthys'' 'fish') is a class that contains the cartilaginous fishes: they are jawed vertebrates with paired fins, paired nares, scales, a heart with its chambers in series, and skeletons made of cartilage rather than bone. The class is divided into two subclasses: Elasmobranchii (sharks, rays, skates, and sawfish) 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. ==Anatomy== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「chondrichthyes」の詳細全文を読む スポンサード リンク
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