[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain "Archaea" Woese et al. 1990 stat. inval. see Domain Archaea Woese et al. 2024
     Phylum "Crenarchaeota" Garrity and Holt 2002 stat. inval. see Phylum Thermoproteota Garrity and Holt 2021
       Class Thermoprotei Reysenbach 2002
         Order Sulfolobales Stetter 1989
           Family Sulfolobaceae Stetter 1989
             Genus Acidianus Segerer et al. 1986
               1 Acidianus infernus Segerer et al. 1986
               2 Acidianus ambivalens (Zillig and Böck 1987) Fuchs et al. 1996
               3 Acidianus brierleyi (Zillig et al. 1980) Segerer et al. 1986