[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Pisces
     Class Osteichthyes Huxley, 1880 - bony fishes and tetrapods see Clade Osteichthyes Huxley 1880 [Moore & Near 2020]
       Order Pleuronectiformes Bleeker, 1859 - flatfishes see Suborder Pleuronectoidei
         Family Scophthalmidae Chabanaud, 1933 - turbots
           Genus Phrynorhombus Günther, 1862
             1 Phrynorhombus norvegicus (Günther, 1862) - Norwegian topknot
             2 Phrynorhombus regius (Bonnaterre, 1788) - Eckström's topknot see Zeugopterus regius (Bonnaterre, 1788)