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"
             ["subviral agents"]
               1 "prions"
               1.1 ["fungi prions"]
               1.2 ["vertebrate prions"]
               2 ["satellites"]
               3 ["viroids"]