[viruses]
   Realm Riboviria
     Order Nidovirales
       Suborder Ronidovirineae
         Family Roniviridae [monotypic]
           Subfamily Okanivirinae [monotypic]
             Genus Okavirus
               Subgenus Tipravirus
                 1 Gill-associated virusᵀ
                 2 Yellow head virus