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]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum Terrabacteria Battistuzzi et al. 2004
               Phylum "Actinobacteria" Garrity and Holt 2001
                 Class Coriobacteriia König 2013
                   Order Eggerthellales Gupta et al. 2013 [monotypic]
                     Family Eggerthellaceaeᵀ Gupta et al. 2013
                       Genus Slackia Wade et al. 1999
                         1 Slackia exigua (Poco et al. 1996) Wade et al. 1999
                         2 Slackia faecicanis Lawson et al. 2005
                         3 Slackia heliotrinireducens corrig. (Lanigan 1983) Wade et al. 1999