[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Pisces
     Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
       Order Hexanchiformes Compagno, 1973 - six-gill sharks
         Family Hexanchidae Gray, 1851 - cow sharks
           Genus Heptranchias Rafinesque, 1810
             1 Heptranchias perlo (Bonnaterre, 1788) - sevengilled shark