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"
             "prions"
               Type mammalian prions
                 01 scrapie prion
                 02 TME prion 1947?
                 03 CWD prion
                 04 BSE prion
                 05 FSE prion
                 06 EUE prion
                 07 Kuru prion
                 08 CJD prion
                 09 GSS prion
                 10 FFI prion