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 fungal prions 1 [URE2] prion 2 [PSI] prion 3 [Het-s] prion