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"
             Order Ortervirales
               1.1 Family Retroviridae
               1.2.1 Family Metaviridae
               1.2.2 Family Caulimoviridae
               2 Family Belpaoviridae [monotypic]
               3 Family Pseudoviridae