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
               Order Nidovirales
                 Suborder Cornidovirineae [monotypic]
                   Family Coronaviridae
                     Subfamily Orthocoronavirinae
                       Genus Gammacoronavirus
                         Subgenus Igacovirus [monotypic]
                           Avian coronavirusᵀ