Chondrichthyes - Taxonomy

Taxonomy

The extant members of the Chondrichthyes are the sharks and rays, belonging to the subclass Elasmobranchii, and the chimaeras, belonging to the subclass Holocephali. Nelson's 2006 Fishes of the World arranges the class as follows:

• Subclass Elasmobranchii
  • †Plesioselachus
  • †Order Squatinactiformes
  • †Order Protacrodontiformes
  • †Infraclass Cladoselachimorpha
    • †Order Cladoselachiformes
  • †Infraclass Xenacanthimorpha
    • †Order Xenacanthiformes
  • Infraclass Euselachii (sharks and rays)
    • †Order Ctenacanthiformes
    • †Division Hybodonta
      • †Order Hybodontiformes
    • Division Neoselachii
      • Subdivision Selachii (modern sharks)
        • Superorder Galeomorphi
          • Order Heterodontiformes (bullhead sharks)
          • Order Orectolobiformes (carpet sharks)
          • Order Lamniformes (mackerel sharks)
          • Order Carcharhiniformes (ground sharks)
        • Superorder Squalomorphi
          • Order Hexanchiformes (frilled and cow sharks)
          • Order Echinorhiniformes (bramble sharks)
          • Order Squaliformes (dogfish sharks)
          • †Order Protospinaciformes
          • Order Squatiniformes (angel sharks)
          • Order Pristiophoriformes (sawsharks)
      • Subdivision Batoidea (rays)
        • Order Torpediniformes (electric rays)
        • Order Pristiformes (sawfishes)
        • Order Rajiformes (skates and guitarfishes)
        • Order Myliobatiformes (stingrays and relatives)
• Subclass Holocephali
  • †Superorder Paraselachimorpha
    • †Order Orodontiformes
    • †Order Petalodontiformes
    • †Order Helodontiformes
    • †Order Iniopterygiformes
    • †Order Debeeriiformes
    • †Order Eugeneodontiformes*
  • Superorder Holocephalimorpha
    • †Order Psammodontiformes*
    • †Order Copodontiformes
    • †Order Squalorajiformes
    • †Order Chondrenchelyiformes
    • †Order Menaspiformes
    • †Order Coliodontiformes
    • Order Chimaeriformes (chimaeras)