Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           ?"viruses"
             Realm Riboviria
               Family Tombusviridae
                 1.1 Subfamily Regressovirinae [monotypic]
                 1.2.1 Genus Avenavirus [monotypic]
                 1.2.2 Subfamily Procedovirinae
                 2 Subfamily Calvusvirinae [monotypic]