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
               Family Retroviridae
                 Subfamily Spumaretrovirinae
                   1.1 Genus Bovispumavirus [monotypic]
                   1.2 Genus Equispumavirus [monotypic]
                   2.1 Genus Felispumavirus [monotypic]
                   2.2.1 Genus Prosimiispumavirus [monotypic]
                   2.2.2 Genus Simiispumavirus