View source for List of Archaea genera

{{Short description|none}}
This article lists the [[genus (biology)|genera]] of the [[Archaea]]. The currently accepted taxonomy is based on the [[List of Prokaryotic names with Standing in Nomenclature]] (LPSN)<ref>{{cite web | author=J.P. Euzéby | url=https://lpsn.dsmz.de/domain/archaea | title=Archaea | publisher=[[List of Prokaryotic names with Standing in Nomenclature]] (LPSN)| access-date=2021-06-27}}</ref> and [[National Center for Biotechnology Information]] (NCBI).<ref>{{cite web |author = Sayers|display-authors = etal| url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=2157 |title=Archaea |accessdate=2021-03-20 |publisher=[[National Center for Biotechnology Information]] (NCBI) taxonomy database}}</ref> However, in the List provided below, [[Genome Taxonomy Database|GTDB]] has precedence unless otherwise noted.

== Phylogeny ==
[[National Center for Biotechnology Information]] (NCBI) taxonomy was initially used to decorate the genome tree via tax2tree. The 16S rRNA-based [[Greengenes]] taxonomy is used to supplement the taxonomy particularly in regions of the tree with no cultured representatives. [[List of Prokaryotic names with Standing in Nomenclature]] (LPSN) is used as the primary taxonomic authority for establishing naming priorities. Taxonomic ranks are normalised using phylorank and the taxonomy manually curated to remove polyphyletic groups.<ref name="pmid30148503">{{cite journal|last1=Parks|first1=DH|last2=Chuvochina|first2=M|last3=Waite|first3=DW|last4=Rinke|first4=C|last5=Skarshewski|first5=A|last6=Chaumeil|first6=PA|last7=Hugenholtz|first7=P|date=November 2018|title=A standardized bacterial taxonomy based on genome phylogeny substantially revises the tree of life.|journal=Nature Biotechnology|volume=36|issue=10|pages=996–1004|biorxiv=10.1101/256800|doi=10.1038/nbt.4229|pmid=30148503|s2cid=52093100}}</ref><ref>{{cite journal|last1=Parks|first1=DH|last2=Chuvochina|first2=M|last3=Chaumeil|first3=PA|last4=Rinke|first4=C|last5=Mussig|first5=AJ|last6=Hugenholtz|first6=P|date=September 2020|title=A complete domain-to-species taxonomy for Bacteria and Archaea.|url=https://www.researchgate.net/publication/340954053|journal=Nature Biotechnology|volume=38|issue=9|pages=1079–1086|biorxiv=10.1101/771964|doi=10.1038/s41587-020-0501-8|pmid=32341564|s2cid=216560589}}</ref><ref>{{cite journal|last1=Chaumeil|first1=PA|last2=Mussig|first2=AJ|last3=Hugenholtz|first3=P|last4=Parks|first4=DH|date=15 November 2019|title=GTDB-Tk: a toolkit to classify genomes with the Genome Taxonomy Database.|journal=Bioinformatics|volume=36 |issue=6 |pages=1925–1927 |doi=10.1093/bioinformatics/btz848|pmc=7703759|pmid=31730192|doi-access=free}}</ref><ref>{{cite journal|last1=Almeida|first1=Alexandre|last2=Nayfach|first2=Stephen|last3=Boland|first3=Miguel|last4=Strozzi|first4=Francesco|last5=Beracochea|first5=Martin|last6=Shi|first6=Zhou Jason|last7=Pollard|first7=Katherine S.|last8=Sakharova|first8=Ekaterina|last9=Parks|first9=Donovan H.|last10=Hugenholtz|first10=Philip|last11=Segata|first11=Nicola|date=20 July 2020|title=A unified catalog of 204,938 reference genomes from the human gut microbiome|journal=Nature Biotechnology|doi=10.1038/s41587-020-0603-3|pmid=32690973|doi-access=free|last12=Kyrpides|first12=Nikos C.|last13=Finn|first13=Robert D.|volume=39|issue=1|pages=105–114|pmc=7801254}}</ref><ref>{{cite journal|last1=Nayfach|first1=Stephen|last2=Roux|first2=Simon|last3=Seshadri|first3=Rekha|last4=Udwary|first4=Daniel|last5=Varghese|first5=Neha|last6=Schulz|first6=Frederik|last7=Wu|first7=Dongying|last8=Paez-Espino|first8=David|last9=Chen|first9=I-Min|last10=Huntemann|first10=Marcel|last11=Palaniappan|first11=Krishna|date=9 November 2020|title=A genomic catalog of Earth's microbiomes|journal=Nature Biotechnology|doi=10.1038/s41587-020-0718-6|doi-access=free|first15=Torben|last16=Kirton|first16=Edward|last17=Faria|last14=Reddy|last18=Edirisinghe|first18=Janaka N.|first19=Christopher S.|last20=Jungbluth|last24=Arkin|first20=Sean P.|last15=Nielsen|last21=Chivian|first21=Dylan|last22=Dehal|first22=Paramvir|last23=Wood-Charlson|first23=Elisha M.|last19=Henry|last28=Mouncey|first24=Adam P.|last29=Ivanova|first14=T. B. K.|first29=Natalia N.|last26=Visel|first26=Axel|last27=Woyke|first27=Tanja|first28=Nigel J.|last30=Kyrpides|first25=Susannah G.|last25=Tringe|first30=Nikos C.|last31=Eloe-Fadrosh|first31=Emiley A.|first13=Supratim|last13=Mukherjee|first12=Joshua|last12=Ladau|first17=José P.|volume=39|issue=4|pages=499–509|pmid=33169036|pmc=8041624|display-authors=1}}</ref>

Cladogram was taken from the [[Genome Taxonomy Database|GTDB]] release 10-RS226 (16th April 2025).<ref name="about">{{cite web |title=GTDB release 10-RS226 |url=https://gtdb.ecogenomic.org/about#4%7C |website=[[Genome Taxonomy Database]]|access-date=1 May 2025}}</ref><ref name="tree">{{cite web |title=ar53_r226.sp_label |url=https://data.gtdb.ecogenomic.org/releases/release226/226.0/auxillary_files/ar53_r226.sp_labels.tree |website=[[Genome Taxonomy Database]]|access-date=1 May 2025}}</ref><ref name="taxon_history">{{cite web |title=Taxon History |url=https://gtdb.ecogenomic.org/taxon_history/ |website=[[Genome Taxonomy Database]]|access-date=1 May 2025}}</ref> The position of clades with a "question mark" are based on the additional phylogeny of the 16S rRNA-based LTP_12_2021 by [[The All-Species Living Tree Project]].<ref>{{cite web|title=The LTP |url=https://imedea.uib-csic.es/mmg/ltp/#LTP| access-date=23 February 2021}}</ref><ref>{{cite web|title=LTP_all tree in newick format| url=https://imedea.uib-csic.es/mmg/ltp/wp-content/uploads/ltp/Tree_LTP_all_12_2021.ntree |access-date=23 February 2021}}</ref><ref>{{cite web|title=LTP_12_2021 Release Notes| url=https://imedea.uib-csic.es/mmg/ltp/wp-content/uploads/ltp/LTP_12_2021_release_notes.pdf |access-date=23 February 2021}}</ref>

{{barlabel|size=8|at2=7|label2=[[Euryarchaeota|Methanobacteriati]]|cladogram=
{{clade|style=font-size:90%; line-height:90%
|label1=Archaea
|1={{Clade
  |1={{Clade
  |label1=[[DPANN|Nanobdellati]]
  |1={{Clade
    |1={{clade
      |1="[[Altarchaeota]]"
      |2={{clade
        |1="[[Iainarchaeota]]"
        |2="[[Micrarchaeota]]"
         }}
       }}
    |2={{Clade
      |1={{clade
      |1="[[Undinarchaeota]]"
         }}
      |2={{clade
        |1={{clade
          |1="[[Huberarchaeaota]]"
          |2={{clade
            |1="[[Aenigmarchaeota]]"
            |2="[[Nanohaloarchaeota|Nanohalarchaeota]]"
             }}
           }}
        |2=[[Nanoarchaeota|Nanobdellota]]
         }}
       }}
     }}
     }}
  |2={{clade
    |1={{clade
    |label1="Methanomada"
    |1={{clade
      |1={{clade
        |1="[[Hadarchaeota]]"|barbegin1=red
        |2=Methanobacteriota_B|bar2=red
         }}
      |2={{clade
        |1="[[Hydrothermarchaeota]]"|bar1=red
        |2=[[Methanobacteriota]]|bar2=red
         }}
       }}
       }}
    |2={{clade
      |1={{clade
        |1=[[Thermoplasmatota]]|bar1=red
        |2=[[Halobacteriota]]|barend2=red
         }}
      |2={{Clade
      |label1="[[Proteoarchaeota]]"
      |1={{Clade
        |1={{Clade
          |label1="Korarchaeota"
          |1="[[Korarchaeota]]"
           }}
        |2={{Clade
          |label1=Promethearchaeati
          |1=[[Asgard (archaea)|Promethearchaeota]]
          |label2=Thermoproteati
          |2=[[Thermoproteota]]
           }}
         }}
         }}
       }}
     }}
   }}
}}
}}

==Phylum [[Microcaldota]]==
===Class Microcaldia===
====Order Microcaldales====
* Family Microcaldaceae <small>Sakai et al. 2023</small>
** ?''[[Microcaldus]]'' <small>Sakai et al. 2023</small>

==Phylum "[[Altarchaeota]]"==
===Class "Altarchaeia"===
====Order "Altarchaeales"====
* Family "Altarchaeaceae" <small>corrig. Probst et al. 2014</small>
** "''Candidatus'' [[Altarchaeum]]" <small>corrig. Probst et al. 2014</small>

==Phylum "[[Iainarchaeota]]"==
===Class "Iainarchaeia"===
====Order "Forterreales"====
* Family "Forterreaceae" <small>Pallen, Rodriguez-R & Alikhan 2022</small>
** "''Candidatus'' [[Forterrea]]" <small>Probst & Banfield 2017</small>

====Order "Iainarchaeales"====
* Family "Iainarchaeaceae" <small>Rinke et al. 2020</small>
** "''Candidatus'' [[Iainarchaeum]]" <small>Rinke et al. 2013</small>

==Phylum "[[Micrarchaeota]]"==
{{cladogram|title=Phylogeny of Micrarchaeota<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{Clade
  |1={{Clade
    |label1="Norongarragalinales"
    |1="''Ca.'' [[Norongarragalina]]"
     }}
  |2={{Clade
    |1={{Clade
      |label1="Micrarchaeales"
      |1={{Clade
        |label1="Micrarchaeaceae"
        |1={{Clade
          |1="''Ca.'' [[Mancarchaeum]]"
          |2="''Ca.'' [[Micrarchaeum]]"
           }}
         }}
       }}
    |2={{Clade
      |1={{Clade
        |label1="Anstonellales"
        |1={{Clade
          |label1="Anstonellaceae"
          |1="''Ca.'' [[Anstonella]]"
          |label2="Bilamarchaeaceae"
          |2="''Ca.'' [[Bilamarchaeum]]"
           }}
         }}
      |2={{Clade
        |1={{Clade
          |label1="Gugararchaeales"
          |1="''Ca.'' [[Gugararchaeum]]"
           }}
        |2={{Clade
          |label1="Burarchaeales"
          |1="''Ca.'' [[Burarchaeum]]"
          |label2="Fermentimicrarchaeales"
          |2="''Ca.'' [[Fermentimicrarchaeum]]"
           }}
         }}
       }}
     }}
   }}
}}
}}

===Class "Micrarchaeia"===
====Order "Norongarragalinales"====
* Family "Norongarragalinaceae" <small>Vázquez-Campos et al. 2021</small>
** "''Candidatus'' [[Norongarragalina]]" <small>Vázquez-Campos et al. 2021</small>

====Order "Micrarchaeales"====
* Family "Micrarchaeaceae" <small>Vázquez-Campos et al. 2021</small>
** "''Candidatus'' [[Mancarchaeum]]" <small>Golyshina et al. 2017</small>
** "''Candidatus'' [[Micrarchaeum]]" <small>Baker et al. 2010</small>

====Order "Anstonellales"====
* Family "Anstonellaceae" <small>Vázquez-Campos et al. 2021</small>
** "''Candidatus'' [[Anstonella]]" <small>Vázquez-Campos et al. 2021</small>
* Family "Bilamarchaeaceae" <small>Vázquez-Campos et al. 2021</small>
** "''Candidatus'' [[Bilamarchaeum]]" <small>Vázquez-Campos et al. 2021</small>

====Order "Gugararchaeales"====
* Family "Gugararchaeaceae" <small>Vázquez-Campos et al. 2021</small>
** "''Candidatus'' [[Gugararchaeum]]" <small>Vázquez-Campos et al. 2021</small>

====Order "Burarchaeales"====
* Family "Burarchaeaceae" <small>Vázquez-Campos et al. 2021</small>
** "''Candidatus'' [[Burarchaeum]]" <small>Vázquez-Campos et al. 2021</small>

====Order "Fermentimicrarchaeales"====
* Family "Fermentimicrarchaeaceae" <small>Kadnikov et al. 2020</small> (Sv326)
** "''Candidatus'' [[Fermentimicrarchaeum]]" <small>Kadnikov et al. 2020</small>

==Phylum "[[Undinarchaeota]]"==
===Class "Undinarchaeia"===
====Order "Undinarchaeales"====
* Family "Naiadarchaeaceae" <small>Dombrowski et al. 2020</small>
** "''Candidatus'' [[Naiadarchaeum]]" <small>Dombrowski et al. 2020</small>
* Family "Undinarchaeaceae" <small>Dombrowski et al. 2020</small>
** "''Candidatus'' [[Undinarchaeum]]" <small>Dombrowski et al. 2020</small>

==Phylum "[[Huberarchaeaota]]"==
===Class "Huberarchaeia"===
====Order "Huberarchaeales"====
* Family "Huberarchaeaceae" <small>Rinke et al. 2020</small>
** "''Candidatus'' [[Huberarchaeum]]" <small>corrig. Schwank et al. 2019</small>

==Phylum "[[Aenigmarchaeota|Aenigmatarchaeota]]"==
===Class "Aenigmatarchaeia"===
====Order "Aenigmatarchaeales"====
* Family "Aenigmatarchaeaceae" <small>corrig. Rinke et al. 2020</small>
** "''Candidatus'' [[Aenigmatarchaeum]]" <small>corrig. Rinke et al. 2013</small>

==Phylum "[[Nanohaloarchaeota|Nanohalarchaeota]]"==
{{cladogram|title=Phylogeny of Nanohalobiales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{Clade
  |1={{Clade
    |label1="Nanohalalkaliarchaeaceae"
    |1="''Candidatus'' [[Nanohalalkaliarchaeum]]"
    |label2="Nanoanaerosalinaceae"
    |2={{Clade
      |1="''Candidatus'' [[Asbonarchaeum]]"
      |2="''Candidatus'' [[Nanoanaerosalina]]"
       }}
     }}
  |2={{Clade
  |label1="Nanohalobiaceae"
  |1={{Clade
    |1="''Candidatus'' [[Nanosalinicola]]"
    |2={{Clade
      |1="''Candidatus'' [[Nanohalococcus]]"
      |2={{Clade
        |1="''Candidatus'' [[Nanohalobium]]"
        |2={{Clade
          |1="''Candidatus'' [[Nanohalovita]]"
          |2="''Candidatus'' [[Nanosalina]]"
           }}
         }}
       }}
     }}
     }}
   }}
}}
}}

===Class "Nanohalarchaeia"===
====Order "Nanohalarchaeales"====
* Family "Nanohalarchaeaceae"
** ?"''Candidatus'' [[Nanohalarchaeum]]" <small>corrig. Hamm et al. 2019</small>
** ?"''Candidatus'' [[Nanopetraeus]]" <small>corrig. Crits‐Christoph et al. 2016</small>
====Order "Nanohydrothermales"====
* Family "Nanohydrothermaceae" <small>Xie et al. 2022</small>
** ?"''Candidatus'' [[Nanohydrothermus]]" <small>Xie et al. 2022</small>
====Order "Nucleotidisoterales"====
* Family "Nanosalenecaceae" <small>Xie et al. 2022</small>
** ?"''Candidatus'' [[Nanosalenecus]]" <small>Xie et al. 2022</small>
* Family "Nucleotidisoteraceae" <small>Xie et al. 2022</small>
** ?"''Candidatus'' [[Nucleotidisoter]]" <small>Xie et al. 2022</small>
* Family "Nucleotidivindicaceae" <small>Xie et al. 2022</small>
** ?"''[[Nucleotidivindex]]''" <small>Xie et al. 2022</small>

===Class "Nanohalobiia"===
====Order "Nanohalobiales"====
* Family "Nanoanaerosalinaceae" <small>Zhao et al. 2022</small>
** "''Candidatus'' [[Asbonarchaeum]]" <small>Baker et al. 2024</small>
** "''Candidatus'' [[Nanoanaerosalina]]" <small>Zhao et al. 2022</small>
* Family "Nanohalalkaliarchaeaceae" <small>La Cono et al. 2020</small>
** "''Candidatus'' [[Nanohalalkaliarchaeum]]" <small>Ghai et al. 2011</small>
* Family "Nanohalobiaceae" <small>La Cono et al. 2020</small>
** ?"''Candidatus'' [[Haloredivivus]]" <small>Ghai et al. 2011</small>
** "''Candidatus'' [[Nanohalobium]]" <small>La Cono et al. 2020</small>
** "''Candidatus'' [[Nanohalococcus]]" <small>Reva et al. 2023</small>
** "''Candidatus'' [[Nanosalina]]" <small>Narasingarao et al. 2012</small>
** "''Candidatus'' [[Nanosalinicola]]" <small>corrig. Narasingarao et al. 2012</small>
** "''Candidatus'' [[Nanohalovita]]" <small>Reva et al. 2023</small>

==Phylum [[Nanoarchaeota|Nanobdellota]]==
{{cladogram|title=Phylogeny of Nanobdellota<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:450px
|1={{Clade
  |1={{Clade
    |1={{Clade
      |1="[[Pacearchaeales]]"
      |2="[[Woesearchaeales]]"
       }}
    |2={{Clade
      |label1=Nanobdellales
      |1={{Clade
        |label1="Nanoarchaeaceae"
        |1="''[[Nanoarchaeum]]''"
        |label2=Nanobdellaceae
        |2={{Clade
          |1="''Ca.'' [[Nanoclepta]]"
          |2=''[[Nanobdella]]''
           }}
         }}
       }}
     }}
  |2={{Clade
    |1={{Clade
    |label1="Tiddalikarchaeales"
    |1={{Clade
      |label1="Tiddalikarchaeaceae"
      |1="''Ca.'' [[Tiddalikarchaeum]]"
       }}
       }}
    |2={{Clade
      |1={{Clade
      |label1="Jingweiarchaeales"
      |1={{Clade
        |label1="Jingweiarchaeaceae"
        |1="''Ca.'' [[Jingweiarchaeum]]"
         }}
         }}
      |2={{Clade
        |label1="JAPDLS01"
        |1={{Clade
          |label1="Haiyanarchaeaceae"
          |1="''Ca.'' [[Haiyanarchaeum]]"
           }}
        |label2="Parvarchaeales"
        |2={{Clade
          |label1="Parvarchaeaceae"
          |1={{Clade
            |1="''Ca.'' [[Rehaiarchaeum]]"
            |2={{Clade
              |1="''Ca.'' [[Acidifodinimicrobium]]"
              |2="''Ca.'' [[Parvarchaeum]]"
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}

===Class Nanobdellia===
====Nanobdellia incertae sedis====
* "[[Mamarchaeales]]"
* "[[Pacearchaeales]]" (DHVE-5, DUSEL-1)
* "[[Wiannamattarchaeales]]" Vazquez-Campos et al. 2019 (LFWA-II, Eury4AB)
* "[[Woesearchaeales]]" (DHVE-6)

====Order JAPDLS01====
* Family "Haiyanarchaeaceae" <small>Rao et al. 2023</small>
** "''Candidatus'' [[Haiyanarchaeum]]" <small>Rao et al. 2023</small>

====Order "Jingweiarchaeales"====
* Family "Jingweiarchaeaceae" <small>Rao et al. 2023</small>
** "''Candidatus'' [[Jingweiarchaeum]]" <small>Rao et al. 2023</small>

====Order Nanobdellales====
* Family "Nanoarchaeaceae" <small>Huber et al. 2011</small>
** "[[Nanoarchaeum]]" <small>Huber et al. 2002</small>
* Family Nanobdellaceae <small>Kato et al. 2022</small> ["Nanopusillaceae" <small>Huber et al. 2011</small>]
** ''[[Nanobdella]]'' <small>Kato et al. 2022</small> ["''Candidatus'' Nanobsidianus" <small>Castelle et al. 2015</small>; "''Candidatus'' [[Nanopusillus]]" <small>Wurch et al. 2016</small>]
** "''Candidatus'' [[Nanoclepta]]" <small>St. John et al. 2019</small>

====Order "Tiddalikarchaeales"====
* Family "Tiddalikarchaeaceae" <small>Vázquez-Campos et al. 2021</small>
** "''Candidatus'' [[Tiddalikarchaeum]]" <small>Vázquez-Campos et al. 2021</small>

====Order "Parvarchaeales"====
* Family "Parvarchaeaceae" <small>Rinke et al. 2020</small>
** "''Candidatus'' [[Acidifodinimicrobium]]" <small>Luo et al. 2020</small> 
** "''Candidatus'' [[Parvarchaeum]]" <small>Baker et al. 2010</small> (ARMAN 4 & 5)
** "''Candidatus'' [[Rehaiarchaeum]]" <small>Rao et al. 2023</small> 

==Phylum [[Asgardaeota|Promethearchaeota]]==
{{cladogram|title=Phylogeny of Promethearchaeota<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{Clade
  |1={{Clade
    |label1="[[Asgardarchaeia]]"
    |1="[[Asgardarchaeales]]"
     }}
  |2={{Clade
    |1={{Clade
      |label1="Atabeyarchaeia"
      |1="[[Atabeyarchaeales]]"
       }}
    |2={{Clade
      |1={{Clade
        |1={{Clade
          |label1="Sifarchaeia"
          |1={{Clade
            |1="[[Borrarchaeales]]"
            |2="[[Sifarchaeales]]"
             }}
           }}
        |2={{Clade
          |1={{Clade
            |label1="Wukongarchaeia"
            |1="[[Wukongarchaeales]]"
             }}
          |2={{Clade
            |label1="Njordarchaeia"
            |1="[[Njordarchaeales]]"
            |label2="[[Heimdallarchaeia]]"
            |2={{Clade
              |1="[[Hodarchaeales]]"
              |2={{Clade
                |1="[[Gerdarchaeales]]" (JABLTI01)
                |2="[[Heimdallarchaeales]]"
                 }}
               }}
             }}
           }}
         }}
      |2={{Clade
        |1={{Clade
          |label1="[[Odinarchaeia]]"
          |1="[[Odinarchaeales]]"
          |label2="Jordarchaeia"
          |2="[[Jordarchaeales]]"
           }}
        |2={{Clade
          |1={{Clade
            |label1="Baldrarchaeia"
            |1="[[Baldrarchaeales]]"
            |label2="[[Thorarchaeia]]"
            |2="[[Thorarchaeales]]"
             }}
          |2={{Clade
            |label1="Hermodarchaeia"
            |1="[[Hermodarchaeales]]"
            |label2=[[Lokiarchaeia|Promethearchaeia]]
            |2={{Clade
              |1="[[Helarchaeales]]"
              |2=[[Promethearchaeales]]
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}

===Promethearchaeota incertae sedis===
* '''Class''' "'''Balderarchaeia'''"
** '''Order''' "'''Balderarchaeales'''"
*** Family "Balderarchaeaceae" (sic) <small>Xie et al. 2022</small>
**** ?"''Candidatus'' [[Balderarchaeum]]" (sic) <small>Xie et al. 2022</small>
* '''Class''' "'''Tyrarchaeia'''"
** '''Order''' "'''Tyrarchaeales'''"
*** Family "Tyrarchaeaceae" <small>Xie et al. 2022</small>
**** ?"''Candidatus'' [[Tyrarchaeum]]" <small>Xie et al. 2022</small>

* '''Class''' "[[Friggarchaeota|Friggarchaeia]]"
* '''Class''' "[[Gefionarchaeota|Gefionarchaeia]]"
* '''Class''' "[[Idunnarchaeota|Idunnarchaeia]]"

===Class "Asgardarchaeia"===
====Order "Asgardarchaeales"====
* Family "Asgardarchaeaceae" <small> <small>Eme et al. 2023 ex Tamarit et al. 2024</small></small>
** "''Candidatus'' [[Asgardarchaeum]]" <small>Eme et al. 2023 ex Tamarit et al. 2024</small>

===Class "Atabeyarchaeia"===
====Order "Atabeyarchaeales"====
* Family "Asgardarchaeaceae" <small> <small>Eme et al. 2023 ex Tamarit et al. 2024</small></small>
** "''Candidatus'' [[Asgardarchaeum]]" <small>Eme et al. 2023 ex Tamarit et al. 2024</small>

===Class "Sifarchaeia"===
====Order "Borrarchaeales"====
* Family "Borrarchaeaceae" <small>Liu et al. 2021</small>
** "''Candidatus'' [[Borrarchaeum]]" <small>Liu et al. 2021</small>

====Order "Sifarchaeales"====
* Family "Sifarchaeaceae" <small>Sun et al. 2021</small>
** "''Candidatus'' [[Sifarchaeum]]" <small>corrig. Farag, Zhao & Biddle 2020</small>

===Class "Wukongarchaeia"===
====Order "Wukongarchaeales"====
* Family "Wukongarchaeaceae" <small>Liu et al. 2021</small>
** "''Candidatus'' [[Wukongarchaeum]]" <small>Liu et al. 2021</small>

===Class "Njordarchaeia"===
====Order "Njordarchaeales"====
* Family "Njordarchaeaceae" <small>Xie et al. 2022</small>
** "''Candidatus'' [[Njordarchaeum]]" <small>Xie et al. 2022</small><ref name="Xie2021">Ruize Xie, Yinzhao Wang, Danyue Huang, Jialin Hou, Liuyang Li, Haining Hu, Xiaoxiao Zhao, Fengping Wang: Expanding Asgard members in the domain of Archaea sheds new light on the origin of eukaryotes. In: ''Science China Life Sciences'', vol. 65, p. 818–829, April 2022. [[doi:10.1007/s11427-021-1969-6]], [[PMID 34378142]]. Epub: Aug. 6, 2021. Along with:[https://www.eurekalert.org/news-releases/932138 Njordarchaeota, a new candidate for a sister group to eukaryotes]. EurekAlert!, Oct. 20, 2021.</ref><ref>[[LPSN]]: [https://lpsn.dsmz.de/order/njordarchaeales Order "''Candidatus'' Njordarchaeales"]</ref>
* Family "Panguiarchaeaceae" <small>Qu et al. 2023</small>
** "''Candidatus'' [[Panguiarchaeum]]" <small>Qu et al. 2023</small>

===Class "[[Heimdallarchaeia]]"===
====Order "Hodarchaeales"====
* Family "Hodarchaeaceae" <small>Liu et al. 2021</small>
** "''Candidatus'' [[Hodarchaeum]]" <small>Liu et al. 2021</small>

====Order "[[Gerdarchaeales]]"====

====Order "Heimdallarchaeales"====
* Family "Kariarchaeaceae" <small>Liu et al. 2021</small>
** "''Candidatus'' [[Kariarchaeum]]" <small>Liu et al. 2021</small>
* Family "Heimdallarchaeaceae" <small>?Wu et al. 2022</small>
** "''Candidatus'' [[Heimdallarchaeum]]" <small>Wu et al. 2022</small><ref name="Wu2022"/>

===Class "[[Odinarchaeia]]"===
====Order "Odinarchaeales"====
* Family "Odinarchaeaceae" <small>Tamarit et al. 2022</small>
** "Candidatus [[Odinarchaeum]]" <small>Tamarit et al. 2022</small>

===Class "Jordarchaeia"===
====Order "Jordarchaeales"====
* Family "Freyrarchaeaceae" <small>Xie et al. 2022</small>
** "''Candidatus'' [[Freyrarchaeum]]" <small>Xie et al. 2022</small><ref name="Xie2021"/><ref>[[LPSN]]: [https://lpsn.dsmz.de/order/freyrarchaeales Order "''Candidatus'' Freyrarchaeales"]</ref>
* Family "Jordarchaeaceae" <small>Sun et al. 2021</small>
** "''Candidatus'' [[Jordarchaeum]]" <small>Sun et al. 2021</small>

===Class "Baldrarchaeia"===
====Order "Baldrarchaeales"====
* Family "Baldrarchaeaceae" <small>corrig. Liu et al. 2021</small>
** "Candidatus [[Baldrarchaeum]]" <small>corrig. Liu et al. 2021</small>

===Class "[[Thorarchaeia]]"===
====Order "Thorarchaeales"====
* Family "[[Thorarchaeaceae]]" (MBG-B)

===Class "Hermodarchaeia"===
====Order "Hermodarchaeales"====
* Family "Hermodarchaeaceae" <small>corrig. Liu et al. 2021</small>
** "''Candidatus'' [[Hermodarchaeum]]" <small>corrig. Liu et al. 2021</small>

===Class [[Lokiarchaeia|Promethearchaeia]]===
====Order "[[Helarchaeota|Helarchaeales]]"====

====Order Promethearchaeales<!-- see https://figshare.com/articles/dataset/Additional_file_4_of_Metagenomes_and_metatranscriptomes_shed_new_light_on_the_microbial-mediated_sulfur_cycle_in_a_Siberian_soda_lake/9723572, currently in GTDB as order CR-4 2023-01-10-->====
In GTDB as order CR-4<!--2023-02-13-->
{{cladogram|title=Phylogeny of Promethearchaeales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:350px
|1={{Clade
  |label1="Sigynarchaeaceae"
  |1="''Ca.'' [[Sigynarchaeum]]"
  |label2=Promethearchaeaceae
  |2={{Clade
    |1=''[[Promethearchaeum]]''
    |2={{Clade
      |1="''Ca.'' [[Harpocratesius]]"
      |2="''Ca.'' [[Lokiarchaeum]]"
       }}
     }}
   }}
}}
}}

* Family "Sigynarchaeaceae" <small>Xie et al. 2022</small><ref name="Xie2021"/><ref>[[LPSN]]: [https://lpsn.dsmz.de/family/sigynarchaeaceae Family "''Candidatus'' Sigynarchaeaceae"]</ref>
** "''Candidatus'' [[Sigynarchaeum]]" <small>Xie et al. 2022</small>
* Family Promethearchaeaceae <small>Imachi et al. 2024</small> ["Lokiarchaeaceae" <small>Vanwonterghem et al. 2016</small>]<!--Poorly documented,  might contain Prometheoarchaeum also, see https://www.studocu.com/ca-es/document/universitat-de-barcelona/aprenentatge-i-ensenyament-de-les-ciencies-naturals/aecn-7b-gx-arqueo-jaba-badia-moreno/42637376 2023-01-13 -->
** "''Candidatus'' [[Harpocratesius]]" <small>Wu ''et al''. 2022</small><ref name="Wu2022">
Fabai Wu, Daan R. Speth, Alon Philosof, Antoine Crémière, Aditi Narayanan, Roman A. Barco, Stephanie A. Connon, Jan P. Amend, Igor A. Antoshechkin, Victoria J. Orphan: Unique mobile elements and scalable gene flow at the prokaryote–eukaryote boundary revealed by circularized Asgard archaea genomes. In: ''[[Nature (journal)|Nature]] Microbiology'' volume 7, p.&nbsp;200–212, Jan 13, 2022. [[doi:10.1038/s41564-021-01039-y]], [[PMID 35027677]], {{PMC|8813620}}. See also [https://www.nature.com/articles/s41564-021-01039-y/figures/8 Extended Data Fig.&nbsp;2].
</ref>
** "''Candidatus'' [[Lokiarchaeum]]" <small>corrig. Spang et al. 2015</small> (MBGB, DSAG)
** ''[[Promethearchaeum]]'' <small>Imachi et al. 2024</small>

==Phylum "[[Korarchaeota]]"==
===Class "Korarchaeia"===
====Order "Korarchaeales"====
* Family "Korarchaeaceae" <small>Rinke et al. 2020</small>
** "''Candidatus'' [[Korarchaeum]]" <small>Elkins et al. 2008</small>
** "''Candidatus'' [[Methanodesulfokora]]" <small>McKay et al. 2019</small>

==Phylum [[Thermoproteota]]==
{{cladogram|title=Phylogeny of Thermoproteota<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{Clade
  |label1="BAT"
  |1={{Clade
    |1={{Clade
      |label1="[[Bathyarchaeia]]"
      |1={{Clade
        |1="[[Bifangarchaeales]]"
        |2={{Clade
          |1={{Clade
            |1="[[Xuanwuarculales]]"
            |2={{Clade
              |1="[[Hecatellales]]"
              |2="[[Houtuarculales]]"
               }}
             }}
          |2={{Clade
            |1="[[Wuzhiqiibiales]]"
            |2={{Clade
              |1="[[Zhuquarculales]]"
              |2="[[Bathyarchaeales]]"
               }}
             }}
           }}
         }}
       }}
    |2={{Clade
      |label1=[[Aigarchaeota|Nitrososphaeria_A]]
      |1="[[Caldarchaeales]]"
      |label2=[[Nitrososphaerota|Nitrososphaeria]]
      |2={{Clade
        |1="[[Geothermarchaeales]]"
        |2={{Clade
          |1=PSMU01
          |2={{Clade
            |1=[[Conexivisphaerales]]
            |2=[[Nitrososphaerales]]
             }}
           }}
         }}
       }}
     }}
  |label2="Sulfobacteria"
  |2={{Clade
    |1={{Clade
      |label1="Methanomethylicia"
      |1={{Clade
        |1="[[Nezhaarchaeales]]"
        |2={{Clade
          |1="[[Culexarchaeles]]"
          |2="[[Methanomethylicales]]"
           }}
         }}
      |label2="[[Thermoprotei]]a"
      |2={{Clade
        |1={{Clade
          |1="[[Gearchaeales]]"
          |2={{Clade
            |1="[[Thermofilales]]"
            |2=[[Thermoproteales]]
             }}
           }}
         }}
       }}
    |2={{Clade
      |label1="Sulfolobia"
      |1={{Clade
        |1="[[Marsarchaeales]]"
        |2=[[Sulfolobales]]
         }}
       }}
     }}
   }}
}}
}}

===Thermoproteota Incertae sedis===
* "[[Brockarchaeia]]"

===Class "[[Bathyarchaeia]]"===
====Order "Bifangarchaeales"====
* Family "Bifangicolaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Bifangicola]]" <small>Hou et al. 2023</small> [3300025546_26]
* Family "Bifangarchaeaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Bifangarchaeum]]" <small>corrig. Hou et al. 2023</small> [B24: DTBU01 sp011374155]
* Family "Bifangistellaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Bifangistella]]" <small>Hou et al. 2023</small> [DRYS01: DRYS01 sp011367275]

====Order "Xuanwuarculales"====
* Family "Mazuisomaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Mazuisoma]]" <small>Hou et al. 2023</small>
* Family "Mazuicellaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Mazuibellus]]" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Mazuicella]]" <small>Hou et al. 2023</small>
* Family "Mazuousiaecae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Mazuarcula]]" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Mazuousia]]" <small>Hou et al. 2023</small>
* Family "Xuanwuarculaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Xuanwuarcula]]" <small>Hou et al. 2023</small> [RBG-16-48-13 sp001775995]

====Order "Hecatellales"====
{{cladogram|title=Phylogeny of "Hecatellaceae"<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{Clade
  |1="''Ca.'' [[Hecatella]]"
  |2={{Clade
    |1= "''Ca.'' [[Jinwuicola]]"
    |2="''Ca.'' [[Jinwuimorpha]]"
     }}
   }}
}}
}}
* Family "Hecatellaceae" <small>Rinke et al. 2020</small>
** ?"''Candidatus'' [[Jinwuarcula]]" <small>Hou et al. 2023</small> [B25]
** ?"''Candidatus'' [[Jinwuimonas]]" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Jinwuiprofundus]]" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Jinwuousia]]" <small>Hou et al. 2023</small> [JdFR-11 sp002011035]
** "''Candidatus'' [[Hecatella]]" <small>Adam et al. 2022</small>
** "''Candidatus'' [[Jinwuicola]]" <small>Hou et al. 2023</small> [EX4484-218 sp002254975]
** "''Candidatus'' [[Jinwuimorpha]]" <small>Hou et al. 2023</small> [EX4484-218 sp003661965]

====Order "Houtuarculales"====
{{cladogram|title=Phylogeny of Houtuarculales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:350px
|1={{Clade
  |1={{Clade
    |label1="Crenohoutuithermaceae"
    |1="''Ca.'' [[Crenohoutuithermus]]"
    |label2="Fontihoutuithermaceae"
    |2="''Ca.'' [[Fontihoutuithermus]]"
     }}
  |2={{Clade
    |label1="Aphrohoutuibellaceae"
    |1={{Clade
      |1="''Ca.'' [[Aphrohoutuibellus]]"
      |2="''Ca.'' [[Hydrohoutuibellus]]"
       }}
    |label2="Houtuousiaceae"
    |2={{Clade
      |1="''Ca.'' [[Houtuousia]]"
      |2="''Ca.'' [[Houtuarcula]]"
       }}
     }}
   }}
}}
}}
* Family "Houtuithermaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Houtuithermus]]" <small>Hou et al. 2023</small>
* Family "Marihoutuimonadaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Houtuibellus]]" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Marihoutuimonas]]" <small>Hou et al. 2023</small>
* Family "Crenohoutuithermaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Crenohoutuithermus]]" <small>Hou et al. 2023</small> [DTDX01]
* Family "Fontihoutuithermaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Fluxihoutuithermus]]" <small>Hou et al. 2023</small> [DTOY01 sp011358085]
** "''Candidatus'' [[Fontihoutuithermus]]" <small>Hou et al. 2023</small> [DTGE01 sp011389385]
* Family "Aphrohoutuibellaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Aphrohoutuibellus]]" <small>Hou et al. 2023</small> [RBG-13-38-9]
** "''Candidatus'' [[Hydrohoutuibellus]]" <small>Hou et al. 2023</small> [DTMT01 sp011355205]
* Family "Houtuousiaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Limnohoutuiplasma]]" <small>Hou et al. 2023</small> 
** "''Candidatus'' [[Houtuarcula]]" <small>Hou et al. 2023</small> [FEN-987]
** "''Candidatus'' [[Houtuousia]]" <small>Hou et al. 2023</small> [40CM-2-53-6]

====Order "Wuzhiqiibiales"====
{{cladogram|title=Phylogeny of "Wuzhiqiibiales"<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{Clade
  |1={{Clade
  |label1="Wuzhiqiimorphaceae"
  |1="''Ca.'' [[Wuzhiqiimorpha]]"
     }}
  |2={{Clade
    |label1="Wuzhiqiimonadaceae"
    |1= "''Ca.'' [[Wuzhiqiimonas]]"
    |label2="Wuzhiqiibiaceae"
    |2="''Ca.'' [[Wuzhiqiibium]]"
     }}
   }}
}}
}}
* Family "Wuzhiqiithermaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Wuzhiqiithermus]]" <small>Hou et al. 2023</small>
* Family "Wuzhiqiitorraceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Wuzhiqiitorris]]" <small>Hou et al. 2023</small>
* Family "Wuzhiqiimorphaceae" <small>Hou et al. 2023</small> 
** "''Candidatus'' [[Wuzhiqiimorpha]]" <small>Hou et al. 2023</small> [PIYN01: PIYN01 sp003601775]
* Family "Wuzhiqiimonadaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Wuzhiqiimonas]]" <small>Hou et al. 2023</small> [B23: B23]
* Family "Wuzhiqiibiaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Wuzhiqiibium]]" <small>Hou et al. 2023</small> [TCS64]

====Order "Zhuquarculales"====
* Family "Zhuquarculaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Zhuquarcula]]" <small>Hou et al. 2023</small> [EX4484-135]
* Family "Zhuquomorphaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Zhuquomorpha]]" <small>Hou et al. 2023</small>

====Order "Bathyarchaeales"====
{{cladogram|title=Phylogeny of "Bathyarchaeales"<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{Clade
  |1={{Clade
  |label1="Pontizhurongicolaceae"
  |1="''Ca.'' [[Pontizhurongicola]]"
     }}
  |2={{Clade
    |1={{Clade
      |label1="Hanbarchaeaceae"
      |1={{Clade
        |1="''Ca.'' [[Hanbarchaeum]]"
        |2={{Clade
          |1="''Ca.'' [[Fufeiimorpha]]"
          |2="''Ca.'' [[Zhurongicella]]"
           }}
         }}
      |label2="Marizhurongicellaceae"
      |2={{Clade
        |1="''Ca.'' [[Marizhurongibium]]"
        |2="''Ca.'' [[Marizhurongicella]]"
         }}
       }}
    |2={{Clade
      |1={{Clade
      |label1="Hanbopyraceae"
      |1="''Ca.'' [[Hanbopyrus]]"
         }}
      |2={{Clade
        |1={{Clade
          |label1="Jingweiiplasmataceae"
          |1= "''Ca.'' [[Jingweiiplasma]]"
          |label2="Bathyarchaeaceae"
          |2={{Clade
            |1="''Ca.'' [[Baizosoma]]"
            |2={{Clade
              |1="''Ca.'' [[Halozhurongicella]]"
              |2={{Clade
                |1="''Ca.'' [[Baizobellus]]"
                |2="''Ca.'' [[Bathyarchaeum]]"
                 }}
               }}
             }}
           }}
        |2={{Clade
        |label1="Bathycorpusculaceae"
        |1={{Clade
          |1="''Ca.'' [[Baizomorpha]]"
          |2={{Clade
            |1="''Ca.'' [[Buyanhuyuitorris]]"
            |2={{Clade
              |1="''Ca.'' [[Buyanhuyuicella]]"
              |2={{Clade
                |1={{Clade
                  |1="''Ca.'' [[Hanbocola]]"
                  |2="''Ca.'' [[Hanbothermus]]"
                   }}
                |2={{Clade
                  |1="''Ca.'' [[Yanziithermus]]"
                  |2={{Clade
                    |1="''Ca.'' [[Yuguotorris]]"
                    |2="''Ca.'' [[Bathycorpusculum]]"
                     }}
                   }}
                 }}
               }}
             }}
           }}
           }}
         }}
       }}
     }}
   }}
}}
}}
* Family "Actozhurongousiaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Actozhurongousia]]" <small>Hou et al. 2023</small>
* Family "Yuguousiaceae" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Yuguousia]]" <small>Hou et al. 2023</small>
* Family "Pontizhurongicolaceae" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Pontizhurongicola]]" <small>Hou et al. 2023</small> [B24-2 sp002490245]
* Family "Hanbarchaeaceae" <small>Hou et al. 2023</small>
** ?"Candidatus [[Limnohoutuiplasma]]" <small>Hou et al. 2023</small>
** "Candidatus [[Houtuarcula]]" <small>Hou et al. 2023</small> [FEN-987]
** "Candidatus [[Houtuousia]]" <small>Hou et al. 2023</small> [40CM-2-53-6]]
* Family "Marizhurongicellaceae" <small>Hou et al. 2023</small> [B26-1]
** ?"Candidatus [[Aoguangisoma]]" <small>Hou et al. 2023</small>
** ?"Candidatus [[Yanziimonas]]" <small>Hou et al. 2023</small>
** ?"Candidatus [[Zhurongibium]]" <small>Hou et al. 2023</small>
** "Candidatus [[Marizhurongibium]]" <small>Hou et al. 2023</small> [B17-G17 sp003662645]
** "Candidatus [[Marizhurongicella]]" <small>Hou et al. 2023</small> [B26-1]
* Family "Hanbopyraceae" <small>Hou et al. 2023</small>
** "Candidatus [[Hanbopyrus]]" <small>Hou et al. 2023</small> [WUQV01 sp009889585]
* Family "Jingweiiplasmataceae" <small>Hou et al. 2023</small>
** "Candidatus [[Jingweiiplasma]]" <small>Hou et al. 2023</small> [SOJC01]
* Family "Bathyarchaeaceae" <small>Khomyakova et al. 2023</small>
** ?"''Candidatus'' [[Baizosediminiarchaeum]]" <small>Yu et al. 2023</small> [BIN-L-1]
** ?"''Candidatus'' [[Baizostella]]" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Baizobellus]]" <small>Hou et al. 2023</small> [SOJZ01]
** "''Candidatus'' [[Baizosoma]]" <small>Hou et al. 2023</small> [BA1 sp001399805]
** "''Candidatus'' [[Bathyarchaeum]]" <small>Khomyakova et al. 2023</small>
** "''Candidatus'' [[Halozhurongicella]]" <small>Hou et al. 2023</small> [B1-G15]
* Family "Bathycorpusculaceae" <small>Loh & Brune 2023</small> [UBA233]
** ?"''Candidatus'' [[Aoshunithermus]]" <small>Hou et al. 2023</small>
** ?"''Candidatus'' [[Baizomonas]]" <small>Hou et al. 2023</small>
** "''Candidatus'' [[Baizomorpha]]" <small>Hou et al. 2023</small> [UBA233]
** "''Candidatus'' [[Bathycorpusculum]]" <small>Loh & Brune 2023</small>
** "''Candidatus'' [[Buyanhuyuicella]]" <small>Hou et al. 2023</small> [SOJA01]
** "''Candidatus'' [[Buyanhuyuitorris]]" <small>Hou et al. 2023</small> [PIYA01]
** "''Candidatus'' [[Hanbocola]]" <small>Hou et al. 2023</small> [DSZD01]
** "''Candidatus'' [[Hanbothermus]]" <small>Hou et al. 2023</small> [DRVP01]
** "''Candidatus'' [[Yanziithermus]]" <small>Hou et al. 2023</small> [JdFR-07]
** "''Candidatus'' [[Yuguotorris]]" <small>Hou et al. 2023</small> [DSLH01]

===Class [[Aigarchaeota|Nitrososphaeria_A]]===
====Order "Caldarchaeales"====
{{cladogram|title=Phylogeny of "Caldarchaeales"<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{Clade
  |1={{Clade
    |label1="Calditenuaceae"
    |1="''Ca.'' [[Calditenuis]]"
    |label2="Caldarchaeaceae"
    |2={{Clade
      |1="''Ca.'' [[Caldarchaeum]]"
      |2="''Ca.'' [[Pelearchaeum]]"
       }}
     }}
  |2={{Clade
  |label1="Wolframiiraptoraceae"
  |1={{Clade
    |1="''Ca.'' [[Terraquivivens]]"
    |2={{Clade
      |1="''Ca.'' [[Geocrenenecus]]"
      |2={{Clade
        |1="''Ca.'' [[Benthortus]]"
        |2="''Ca.'' [[Wolframiiraptor]]"
         }}
       }}
     }}
     }}
   }}
}}
}}
* Family "Calditenuaceae" <small>Balbay et al. 2023</small>
** "''Candidatus'' [[Calditenuis]]" <small>Beam et al. 2016</small>
* Family "Caldarchaeaceae" <small>Rinke et al. 2020</small>
** "''Candidatus'' [[Caldarchaeum]]" <small>corrig. Nunoura et al. 2011</small>
** "''Candidatus'' [[Pelearchaeum]]" <small>Balbay et al. 2023</small>
* Family "Wolframiiraptoraceae" <small>Buessecker et al. 2022</small>
** "''Candidatus'' [[Benthortus]]" <small>Buessecker et al. 2022</small>
** "''Candidatus'' [[Geocrenenecus]]" <small>Buessecker et al. 2022</small>
** "''Candidatus'' [[Terraquivivens]]" <small>Buessecker et al. 2022</small>
** "''Candidatus'' [[Wolframiiraptor]]" <small>Buessecker et al. 2022</small>

===Class [[Nitrososphaerota|Nitrososphaeria]]===
====Nitrososphaeria Incertae sedis====
* "''[[Cenoporarchaeum]]''" <small>corrig. Zhang et al. 2019</small>
* "''Candidatus'' [[Gigantothauma]]" <small>corrig. Muller et al. 2010</small>
* "''Candidatus'' [[Nitrosodeserticola]]" <small>Hwang et al. 2021</small>

====Order "Nitrosomirales"====
* Family "[[Nitrosomiraceae]]" <small>Zheng et al. 2024</small>
** ?"''Candidatus'' [[Nitrosomirus]]" <small>Zheng et al. 2024</small>

====Order "Geothermarchaeales"====
* Family "[[Geothermarchaeaceae]]" <small>Adam et al. 2022</small>
** "''Candidatus'' [[Geothermarchaeum]]" <small>Adam et al. 2022</small>
** "''Candidatus'' [[Scotarchaeum]]" <small>Adam et al. 2022</small>

====Order PSMU01====
* Family PSMU01
** "''Candidatus'' [[Australarchaeum]]" <small>Herbold et al. 2024</small>

====Order "Conexivisphaerales"====
* Family "Conexivisphaeraceae" <small>Kato et al. 2021</small> (THSC Group)
** ''[[Conexivisphaera]]'' <small>Kato et al. 2021</small>

====Order [[Nitrososphaerales]]====
{{cladogram|title=Phylogeny of Nitrososphaerales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:350px
|1={{Clade
  |1={{Clade
    |label1="Gagatemarchaeaceae"
    |1="''Ca.'' [[Gagatemarchaeum]]"
     }}
  |2={{Clade
    |1={{Clade
      |label1="Nitrosocaldaceae"
      |1={{Clade
        |1="''Ca.'' [[Nitrosothermus]]"
        |2="''Ca.'' [[Nitrosocaldus]]"
         }}
       }}
    |2={{Clade
      |label1=[[Nitrososphaeraceae]]
      |1={{Clade
        |1="''Ca.'' [[Nitrosocosmicus]]"
        |2={{Clade
          |1=''[[Nitrososphaera]]''
          |2="''Ca.'' [[Nitrosopolaris]]"
           }}
         }}
      |label2=[[Nitrosopumilaceae]]
      |2={{Clade
        |1="''Ca.'' [[Nitrosotalea]]"
        |2={{Clade
          |1="''Ca.'' [[Nitrosotenuis]]"
          |2={{Clade
            |1="''Ca.'' [[Nitrosopelagicus]]"
            |2={{Clade
              |1={{Clade
                |1="''[[Cenarchaeum]]''"
                |2="''Ca.'' [[Nitrosoabyssus]]"
                 }}
              |2={{Clade
                |1='' [[Nitrosarchaeum]]''
                |2={{Clade
                  |1="''Ca.'' [[Nitrosomaritimum]]"
                  |2='' [[Nitrosopumilus]]''
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}
* Family "Methylarchaceae" <small>Hua et al. 2019</small>
** ?"''Candidatus'' [[Methylarchaeum]]" <small>Hua et al. 2019</small>
** ?"''Candidatus'' [[Methanotowutia]]" <small>Ou et al. 2022</small>
* Family "Gagatemarchaeaceae" <small>Sheridan et al. 2023</small> [UBA183]
** ?"''Candidatus'' [[Subgagatemarchaeum]]" <small>Sheridan et al. 2023</small> [Fn1; IMG2558309099]
** "''Candidatus'' [[Gagatemarchaeum]]" <small>Sheridan et al. 2023</small> [Bog-1369; GCA_003164815.1]
* Family "Nitrosocaldaceae" <small>Qin et al. 2016</small>
** "''Candidatus'' [[Nitrosocaldus]]" <small>de la Torre et al. 2008</small>
** "''Candidatus'' [[Nitrosothermus]]" <small>Luo et al. 2021</small>
* Family [[Nitrososphaeraceae]] <small>Stieglmeier et al. 2014</small>
** "''Candidatus'' [[Nitrosocosmicus]]" <small>corrig. Lehtovirta-Morley et al. 2016</small>
** "''Candidatus'' [[Nitrosopolaris]]" <small>Pessi, Rutanen & Hultman 2022</small>
** ''[[Nitrososphaera]]'' <small>Stieglmeier et al. 2014</small>
* Family [[Nitrosopumilaceae]] <small>Qin et al. 2017</small>
** "''[[Cenarchaeum]]''" <small>DeLong & Preston 1996</small>
** ''[[Nitrosarchaeum]]'' <small>corrig. Jung et al. 2018</small>
** ?"''Candidatus'' [[Candidatus Nitrosoabyssus]]" <small>Garritano et al. 2024</small>
** ?"''Candidatus'' [[Candidatus Nitrosokoinonia]]" <small>Glasl et al. 2023</small>
** ?"''Candidatus'' [[Candidatus Nitrosomaritimum]]" <small>Zhao et al. 2024</small>
** "''Candidatus'' [[Nitrosopelagicus]]" <small>Santoro et al. 2015</small>
** ''[[Nitrosopumilus]]'' <small>Qin et al. 2017</small> ["''Candidatus'' Nitrosomarinus" <small>Ahlgren et al. 2017</small>]
** ?"''Candidatus'' [[Nitrosospongia]]" <small>Moeller et al. 2019</small>
** "''Candidatus'' [[Nitrosotalea]]" <small>Lehtovirta 2011</small>
** "''Candidatus'' [[Nitrosotenuis]]" <small>Lebedeva et al. 2013</small>

===Class "Methanomethylicia"===
====Methanomethylicia incertae sedis====
* '''Order''' "'''Methanohydrogenicales'''"
** Family "Methanohydrogenicaceae" <small>Berghuis et al. 2019</small>
*** ?"''Candidatus'' [[Methanohydrogenicus]]" <small>Berghuis et al. 2019</small>

* '''Order''' "'''Methanomethylarchaeales'''"
** Family "Methanomethylarchaeceae" <small>corrig. Hua et al. 2019</small>
*** ?"''Candidatus'' [[Methanomethylarchaeum]]" <small>corrig. Hua et al. 2019</small>

* '''Order''' "'''Methanomethylovorales'''"
** Family "Methanomethylovoraceae" <small>Hua et al. 2019</small>
*** ?"''Candidatus'' [[Methanomethylovorus]]" <small>Hua et al. 2019</small>

====Order "Nezhaarchaeales"====
* Family "Methanohydrogenotrophicaceae" <small>Hua et al. 2019</small>
** ?"''Candidatus'' [[Methanogearchaeum]]" <small>corrig. Hua et al. 2019</small>
** ?"''Candidatus'' [[Methanohydrogenotrophicum]]" <small>Hua et al. 2019</small>

====Order "Culexarchaeles"====
* Family "Culexarchaeaceae" <small>Kohtz et al. 2022</small> ["Methanomediaceae" <small>Berghuis et al. 2019</small>]
** "''Candidatus'' [[Culexarchaeum]]" <small>Kohtz et al. 2022</small> ["''Candidatus'' Methanomedium" <small>Berghuis et al. 2019</small>]
* Family "Culexmicrobiaceae" <small>Kohtz et al. 2022</small>
** "''Candidatus'' [[Culexmicrobium]]" <small>Kohtz et al. 2022</small>

====Order "Methanomethylicales"====
* Family "Candidatus Methanomethylicaceae" <small>corrig. Vanwonterghem et al. 2016</small>
** ?"''Candidatus'' [[Methanoluiimicrobium]]" <small>Wu et al. 2024</small>
** "''Candidatus'' [[Methanomethylicus]]" <small>Vanwonterghem et al. 2016</small>
** ?"''Candidatus'' [[Methanostamsia]]" <small>Wu et al. 2024</small>
** "''Candidatus'' [[Methanosuratinicola]]" <small>corrig. Vanwonterghem et al. 2016</small>

===Class [[Thermoprotei]]a===
====Order "Gearchaeales"====
* Family "Gearchaeaceae" <small>corrig.</small>
** ?''[[Geoarchaeum]]'' <small>(sic) Hunt et al. 2016</small>

====Order Thermofilales====
* Family [[Thermofilaceae]] <small>Burggraf, Huber & Stetter 1997</small>
** ''[[Infirmifilum]]'' <small>Zayulina et al. 2021</small>
** ''[[Thermofilum]]'' <small>Zillig & Gierl 1983</small>

====Order [[Thermoproteales]]====
{{cladogram|title=Phylogeny of Thermoproteales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{clade
  |label1=Thermocladiaceae
  |1={{clade
    |2=''[[Vulcanisaeta]]''
    |1={{clade
      |1=''[[Caldivirga]]''
      |2=''[[Thermocladium]]''
       }}
     }}
  |label2=Thermoproteaceae
  |2={{clade
    |1=''[[Thermoproteus]]''
    |2=''[[Pyrobaculum]]''
     }}
   }}
}}
}}
* Family Thermocladiaceae <small>Chuvochina et al. 2024</small>
** ''[[Caldivirga]]'' <small>Itoh et al. 1999</small>
** ''[[Thermocladium]]'' <small>Itoh, Suzuki & Nakase 1998</small>
** ''[[Vulcanisaeta]]'' <small>Itoh, Suzuki & Nakase 2002</small>
* Family [[Thermoproteaceae]] <small>Zillig & Stetter 1982</small>
** ''[[Pyrobaculum]]'' <small>Huber, Kristjansson & Stetter 1988</small>
** ''[[Thermoproteus]]'' <small>Zillig & Stetter 1982</small>

===Class "Sulfolobia"===
====Order "Marsarchaeales"====
* Family "[[Marsarchaeaceae]]" <small></small>

====Order [[Sulfolobales]]====
{{cladogram|title=Phylogeny of Sulfolobales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{clade
  |1={{clade
    |1={{clade
      |label1=[[Desulfurococcaceae]]
      |1={{clade
        |1=''[[Staphylothermus]]''
        |2={{clade
          |1=''[[Thermogladius]]''
          |2={{clade
            |1=''[[Thermosphaera]]''
            |2=''[[Desulfurococcus]]''
             }}
           }}
         }}
       }}
    |2={{clade
      |1={{clade
        |label1=[[Fervidicoccaceae]]
        |1=''[[Fervidicoccus]]''
         }}
      |2={{clade
        |label1=[[Pyrodictiaceae]]
        |1={{clade
          |1=''[[Pyrolobus]]''
          |2={{clade
            |1=''[[Hyperthermus]]''
            |2={{clade
              |1=''[[Pyrofollis]]''
              |2=''[[Pyrodictium]]''
               }}
             }}
           }}
        |label2=[[Acidilobaceae]]
        |2={{clade
          |1="''Ca.'' [[Tiamatella]]"
          |2={{clade
            |1="''Ca.'' [[Calypsonella]]"
            |2={{clade
              |1={{clade
                |1=''[[Thermodiscus]]''
                |2=''[[Aeropyrum]]''
                 }}
              |2={{clade
                |1=''[[Caldisphaera]]''
                |2=''[[Acidilobus]]''
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
  |2={{clade
    |1={{clade
      |label1=Ignisphaeraceae
      |1=''[[Ignisphaera]]''
      |label2="Zestosphaeraceae"
      |2=''[[Zestosphaera]]''
       }}
    |2={{clade
      |label1=Ignicoccaceae
      |1=''[[Ignicoccus]]''
      |label2=[[Sulfolobaceae]]
      |2={{clade
        |1=''[[Sulfodiicoccus]]''
        |2={{clade
          |1={{clade
            |1=''[[Sulfurisphaera]]''
            |2={{clade
              |1=''[[Stygiolobus]]''
              |2=''[[Sulfolobus]]''
               }}
             }}
          |2={{clade
            |1={{clade
              |1=''[[Sulfuracidifex]]''
              |2=''[[Saccharolobus]]''
               }}
            |2={{clade
              |1=''[[Metallosphaera]]''
              |2={{clade
                |1="''Ca.'' [[Aramenus]]"
                |2=''[[Acidianus]]''
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}
* Family [[Desulfurococcaceae]] <small>Zillig & Stetter 1983</small>
** ?''[[Caldococcus]]'' <small>Aoshima, Yamagishi & Oshima 1996</small>
** ''[[Desulfurococcus]]'' <small>Zillig & Stetter 1983</small>
** ''[[Staphylothermus]]'' <small>Stetter & Fiala 1986</small>
** ?''[[Sulfophobococcus]]'' <small>Hensel et al. 1997</small>
** ''[[Thermogladius]]'' <small>Osburn & Amend 2011 ex Kochetkova et al. 2016</small>
** ''[[Thermosphaera]]'' <small>Huber et al. 1998</small>
** ?"''Candidatus'' [[Zestomicrobium]]" <small>Dzhuraeva, Bobodzhanova & Birkeland 2024</small>
* Family [[Fervidicoccaceae]] <small>Perevalova et al. 2010</small>
** ''[[Fervidicoccus]]'' <small>Perevalova et al. 2010</small>
* Family [[Pyrodictiaceae]] <small>Burggraf, Huber & Stetter 1997</small>
** ?''[[Geogemma]]'' <small>Kashefi, Holmes & Lovley 2006</small>
** ''[[Hyperthermus]]'' <small>Zillig, Holz & Wunderl 1991</small>
** ''[[Pyrodictium]]'' <small>Stetter, König & Stackebrandt 1984</small>
** "''[[Pyrofollis]]''" <small>Miyazaki et al. 2023</small>
** ''[[Pyrolobus]]'' <small>Blochl et al. 1999</small>
* Family Ignicoccaceae <small>Chuvochina et al. 2024</small>
** ''[[Ignicoccus]]'' <small>Huber, Burggraf & Stetter 2000</small>
* Family [[Acidilobaceae]] <small>Prokofeva et al. 2009</small>
** ''[[Aeropyrum]]'' <small>Sako et al. 1996</small>
** ''[[Acidilobus]]'' <small>Prokofeva et al. 2000</small>
** ''[[Caldisphaera]]'' <small>Itoh et al. 2003</small>
** "''Candidatus'' [[Calypsonella]]" <small>St John and Reysenbach 2024</small>
** ?"''Candidatus'' [[Hestiella]]" <small>St-John and Reysenbach 2024</small>
** ?''[[Stetteria]]'' <small>Jochimsen, Peinemann-Simon & Thomm 1998</small>
** ''[[Thermodiscus]]'' <small>Stetter 2003</small>
** "''Candidatus'' [[Tiamatella]]" <small>St John and Reysenbach 2024</small>
* Family Ignisphaeraceae <small>RChuvochina et al. 2024</small>
** ''[[Ignisphaera]]'' <small>Niederberger et al. 2006</small>
* Family "Zestosphaeraceae" <small>Pallen, Rodriguez-R & Alikhan 2022</small>
** ''[[Zestosphaera]]'' <small>St. John et al. 2021</small>
* Family [[Sulfolobaceae]] <small>Stetter 1989</small>
** ''[[Acidianus]]'' <small>Segerer et al. 1986</small> ["''Sulfosphaerellus''" <small>Zhong et al. 1982</small>; ''Desulfurolobus'' <small>Zillig & Böck 1987</small>]
** "''Candidatus'' [[Aramenus]]" <small>Servín-Garcidueñas & Martínez-Romero 2014</small>
** ''[[Metallosphaera]]'' <small>Huber et al. 1989</small>
** ''[[Saccharolobus]]'' <small>Sakai & Kurosawa 2018</small>
** ''[[Stygiolobus]]'' <small>Segerer et al. 1991</small>
** ''[[Sulfodiicoccus]]'' <small>Sakai & Kurosawa 2017</small>
** ''[[Sulfolobus]]'' <small>Brock et al. 1972</small>
** ''[[Sulfuracidifex]]'' <small>Itoh et al. 2020</small>
** ''[[Sulfurisphaera]]'' <small>Kurosawa et al. 1998</small>
** ?''[[Sulfurococcus]]'' <small>Golovacheva, Vale’kho & Troitskii 1995</small>

==Phylum "[[Hadarchaeota]]"==
===Class "[[Persephonarchaeia]]"===
===Class "Hadarchaeia"===
====Order "Hadarchaeales"====
* Family "Cerberiarchaeaceae" <small>Benito Merino et al. 2024</small>
** ?"''Candidatus'' [[Cerberiarchaeum]]" <small>Benito Merino et al. 2024</small>
** ?"''Candidatus'' [[Melinoarchaeum]]" <small>Yu et al. 2024</small>
* Family "Hadarchaeaceae" <small>Chuvochina et al. 2019 ex Chuvochina et al. 2023</small>
** "''Candidatus'' [[Hadarchaeum]]" <small>Chuvochina et al. 2019</small>
** ?"''Candidatus'' [[Hadesarchaeum]]" <small>Hua et al. 2019</small>
** ?"''Candidatus'' [[Methanourarchaeum]]" <small>Hua et al. 2019</small>

==Phylum Methanobacteriota_B==
{{cladogram|title=Phylogeny of Methanobacteriota_B<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{clade
  |label1=[[Thermococci]]
  |1={{clade
    |label1="Methanofastidiales"
    |sublabel1="Methanofastidiosaceae"
    |1="''Ca.'' [[Methanofastidiosum]]"
    |label2=[[Thermococcales]]
    |sublabel2=[[Thermococcaceae]]
    |2={{clade
      |1=''[[Palaeococcus]]''
      |2={{clade
        |1=''[[Thermococcus]]''_A
        |2={{clade
          |1=''[[Thermococcus]]''_B
          |2={{clade
            |1=''[[Pyrococcus]]''
            |2=''[[Thermococcus]]''
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}

===Class "[[Theionarchaeia]]"===
===Class [[Thermococci]]===
====Order "Methanofastidiosales"====
* Family "Methanofastidiosaceae" <small>Rinke et al. 2020</small>
** "''Candidatus'' [[Methanofastidiosum]]" <small>corrig. Nobu et al. 2016</small>

====Order [[Thermococcales]]====
* Family [[Thermococcaceae]] <small>Zillig et al. 1988</small>
** ''[[Palaeococcus]]'' <small>Takai et al. 2000</small>
** ''[[Pyrococcus]]'' <small>Fiala & Stetter 1986</small>
** ''[[Thermococcus]]'' <small>Zillig 1983</small>

==Phylum "[[Hydrothermarchaeota]]"==
===Class "Hydrothermarchaeia"===
====Order "Hydrothermarchaeales"====
* Family BMS3B
** "''Candidatus'' [[Pyrohabitans]]" <small>Adam et al. 2022</small>
* Family "Hydrothermarchaeaceae" <small>Chuvochina et al. 2019</small>
** "''Candidatus'' [[Hydrothermarchaeum]]" <small>Chuvochina et al. 2019</small>

==Phylum [[Methanobacteriota]]==
{{cladogram|title=Phylogeny of Methanobacteriota<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:500px
|1={{clade
  |1={{clade
  |label1="[[Methanococci|Methanococcia]]"
  |sublabel1=[[Methanococcales]]
  |1={{clade
    |label1=[[Methanocaldococcaceae]]
    |1=''[[Methanocaldococcus]]''
    |label2=[[Methanococcaceae]]
    |2={{clade
      |1=''[[Methanotorris]]''
      |2={{clade
        |1=''[[Methanofervidicoccus]]''
        |2={{clade
          |1=''[[Methanothermococcus]]''
          |2=''[[Methanococcus]]''
           }}
         }}
       }}
     }}
     }}
  |2={{clade
    |label1="[[Methanopyri|Methanopyria]]"
    |sublabel1=[[Methanopyrales]]
    |1={{clade
      |label1=[[Methanopyraceae]]
      |1=''[[Methanopyrus]]''
       }}
    |label2="[[Methanobacteria|Methanobacteriia]]"
    |sublabel2=[[Methanobacteriales]]
    |2={{clade
      |1={{clade
        |label1=[[Methanothermaceae]]
        |1=''[[Methanothermus]]''
         }}
      |2={{clade
        |1={{clade
          |label1=Methanothermobacteraceae_A
          |1=''Methanothermobacter''_A
           }}
        |2={{clade
          |label1=Methanothermobacteraceae
          |1=''[[Methanothermobacter]]''
          |label2=[[Methanobacteriaceae]]
          |2={{clade
            |1={{clade
              |1={{clade
                |1="''[[Methanacia]]''"
                |2={{clade
                  |1="''[[Methanoflexus]]''"
                  |2="''[[Methanovirga]]''"
                   }}
                 }}
              |2={{clade
                |1={{clade
                  |1="''[[Methanorudis]]''"
                  |2={{clade
                    |1="''[[Methanobaculum]]''"
                    |2="''[[Methanobinarius]]''"
                     }}
                   }}
                |2={{clade
                  |1="''[[Methanocatella]]''"
                  |2={{clade
                    |1="''[[Methanarmilla]]''"
                     |2=''[[Methanobrevibacter]]''
                     }}
                   }}
                 }}
               }}
            |2={{clade
              |1=''[[Methanobacterium]]''_E & F
              |2={{clade
                |1=''[[Methanobacterium]]''_D
                |2={{clade
                  |1=''[[Methanosphaera]]''
                  |2=''[[Methanobacterium]]''
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}

===Class "[[Methanococci|Methanococcia]]"===
====Order [[Methanococcales]]====
*Family [[Methanocaldococcaceae]] <small>Whitman 2002</small>
** ''[[Methanocaldococcus]]'' <small>Whitman 2002</small>
* Family [[Methanococcaceae]] <small>Balch & Wolfe 1981</small>
** ''[[Methanococcus]]'' <small>Kluyver & van Niel 1936</small>
** ''[[Methanofervidicoccus]]'' <small>Sakai et al. 2019</small>
** ''[[Methanothermococcus]]'' <small>Whitman 2002</small>
** ''[[Methanotorris]]'' <small>Whitman 2002</small> ["''Methanoignis''" <small>Boone, Whitman & Rouviére 1993</small>]

===Class [[Methanopyri|Methanopyria]]===
====Order [[Methanopyrales]]====
* Family [[Methanopyraceae]] <small>Huber & Stetter 2002</small>
** ''[[Methanopyrus]]'' <small>Kurr et al. 1992</small>

===Class [[Methanobacteria|Methanobacteriia]]===
====Order [[Methanobacteriales]]====
* Family "Tepidaquicellaceae" <small>corrig. Kadnikov et al. 2020</small>
** ?"''Candidatus'' [[Tepidaquicella]]" <small>corrig. Kadnikov et al. 2020</small>
* Family [[Methanothermaceae]] <small>Stetter et al. 1982</small>
** ''[[Methanothermus]]'' <small>Stetter et al. 1982</small>
* Family Methanothermobacteraceae <small>Chuvochina et al. 2024</small>
** ''[[Methanothermobacter]]'' <small>Wasserfallen et al. 2000</small>
* Family [[Methanobacteriaceae]] <small>Barker 1956</small> 
** "''[[Methanacia]]''" <small>Protasov & Brune 2023</small>
** "''[[Methanarmilla]]''" <small>Protasov & Brune 2023</small>
** ''[[Methanobacterium]]'' <small>Kluyver & van Niel 1936</small>
** "''[[Methanobaculum]]''" <small>Protasov & Brune 2023</small>
** "''[[Methanobinarius]]''" <small>Protasov & Brune 2023</small>
** ''[[Methanobrevibacter]]'' <small>Balch & Wolfe 1981</small>
** "''[[Methanocatella]]''" <small>Protasov & Brune 2023</small>
** "''[[Methanoflexus]]''" <small>Protasov & Brune 2023</small>
** "''[[Methanorudis]]''" <small>Protasov & Brune 2023</small>
** ''[[Methanosphaera]]'' <small>Miller & Wolin 1985</small>
** "''[[Methanovirga]]''" <small>Protasov & Brune 2023</small>

==Phylum [[Thermoplasmatota]]==
{{cladogram|title=Phylogeny of Thermoplasmatota<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:350px
|1={{clade
  |1={{clade
    |label1="Izemarchaea"
    |1="[[Thermoprofundales]]"
     }}
  |2={{clade
    |label1="Poseidoniia"
    |1={{clade
      |1=MGIII
      |2="[[Poseidoniales]]"
       }}
    |label2="[[Thermoplasmata|Thermoplasmatia]]"
    |2={{clade
      |1={{clade
        |1={{clade
          |1="[[Proteinoplasmatales]]" 
          |2="[[Yaplasmatales]]"
           }}
        |2={{clade
          |1="[[Gimiplasmatales]]"
          |2={{clade
            |1="[[Sysuiplasmatales]]"
            |2=[[Methanomassiliicoccales]]
             }}
           }}
         }}
      |2={{clade
        |1="[[Halarchaeoplasmatales]]"
        |2={{clade
          |1="[[Lutacidiplasmatales]]"
          |2={{clade
            |1="[[Aciduliprofundales]]"
            |2="[[Thermoplasmatales]]"
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}

===Class "Izemarchaea"===
====Order "[[Thermoprofundales]]"====
* (MBG-D, E2)

===Class "Poseidoniia"===
====Order MGIII====
====Order "Poseidoniales"====
* Family "Poseidoniaceae" <small>corrig. Rinke et al. 2019</small>
** "''Candidatus'' [[Poseidonia]]" <small>Rinke et al. 2019</small>
* Family "Thalassarchaeaceae" <small>corrig. Rinke et al. 2019</small>
** "''Candidatus'' [[Thalassarchaeum]]" <small>corrig. Martin-Cuadrado et al. 2015</small>

===Class [[Thermoplasmata]]===
====Order "Lunaplasmatales"====
* Family "Lunaplasmataceae" <small>Zinke et al. 2021</small>
** ?"''Candidatus'' [[Lunaplasma]]" <small>Zinke et al. 2021</small>

====Order "Proteinoplasmatales"====
* (SG8-5)

====Order "[[Yaplasmatales]]"====
* (RBG-16-68-12)

====Order "Gimiplasmatales"====
* Family "Gimiplasmataceae" <small>Hu et al. 2020</small>
** "''Candidatus'' [[Gimiplasma]]" <small>Hu et al. 2020</small> (UA10834)

====Order "Sysuiplasmatales"====
* Family "Sysuiplasmataceae" <small>Yuan et al. 2021</small>
** "''Candidatus'' [[Sysuiplasma]]" <small>Yuan et al. 2021</small>

====Order [[Methanomassiliicoccales]]====
{{cladogram|title=Phylogeny of Methanomassiliicoccales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:350px
|1={{clade
  |label1=[[Methanomassiliicoccaceae]]
  |1=''[[Methanomassiliicoccus]]''
  |label2=Methanomethylophilaceae
  |2={{clade
    |1="''Candidatus'' [[Methanomicula]]"
    |2={{clade
      |1="''[[Methanarcanum]]''"
      |2={{clade
        |1="''[[Methanoprimaticola]]''"
        |2={{clade
          |1=''[[Methanomethylophilus]]''
          |2={{clade
            |1="''[[Methanogranum]]''"
            |2="''[[Methanoplasma]]''"
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}
* Family "Methanomixtatrophicaceae" <small>Hua et al. 2019</small>
** ?"''Candidatus'' [[Methanomixtatrophicum]]" <small>Hua et al. 2019</small>
* Family [[Methanomassiliicoccaceae]] <small>Iino et al. 2013</small>
** ''[[Methanomassiliicoccus]]'' <small>Dridi et al. 2012</small>
* Family Methanomethylophilaceae <small>Gaci et al. 2014 ex Borrel et al. 2024</small>
** "''[[Methanarcanum]]''" <small>Chibani et al. 2023</small>
** "''[[Methanogranum]]''" <small>Iino et al. 2023</small>
** ''[[Methanomethylophilus]]'' <small>corrig. Borrel et al. 2024</small>
** "''Candidatus'' [[Methanomicula]]" <small>Protasov & Brune 2023</small>
** "''[[Methanoplasma]]''" <small>Lang & Brune 2023</small>
** "''[[Methanoprimaticola]]''" <small>Chibani et al. 2023</small>
** ?"''Candidatus'' [[Methanospyradousia]]" <small>Gilroy et al. 2021</small>

====Order "Halarchaeoplasmatales"====
{{cladogram|title=Phylogeny of Halarchaeoplasmatales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{clade
  |1={{clade
    |1="''Candidatus'' [[Haladaptiplasma]]"
    |2="''Candidatus'' [[Halarchaeoplasma]]"
     }}
  |2={{clade
    |1="''Candidatus'' [[Natronoplasma]]"
    |2="''Candidatus'' [[Saliniplasma]]"
     }}
   }}
}}
}}
* Family "Halarchaeoplasmataceae" <small>Zhou et al. 2023</small> (PWKY01)
** "''Candidatus'' [[Haladaptiplasma]]" <small>corrig. Zhou et al. 2022</small>
** "''Candidatus'' [[Halarchaeoplasma]]" <small>Zhou et al. 2023</small> ["''Candidatus'' [[Haloplasma]]" <small>Zhou et al. 2022 non Antunes et al. 2008</small>]
** "''Candidatus'' [[Natronoplasma]]" <small>Zhou et al. 2022</small>
** "''Candidatus'' [[Saliniplasma]]" <small>Zhou et al. 2022</small>

====Order "Lutacidiplasmatales"====
* Family "Lutacidiplasmataceae" <small>Sheridan et al. 2022</small>
** "''Candidatus'' [[Lutacidiplasma]]" <small>Sheridan et al. 2022</small> (UBA184)

====Order "Aciduliprofundales"====
* Family "Aciduliprofundaceae" <small>Rinke et al. 2020</small>
** "''[[Aciduliprofundum]]''" <small>Reysenbach et al. 2006</small> (DHVE2 group)

====Order [[Thermoplasmatales]]====
{{cladogram|title=Phylogeny of Thermoplasmatales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{clade
  |1=''[[Thermoplasma]]''
  |2={{clade
    |1={{clade
      |1=''[[Cuniculiplasma]]''
      |2=''[[Thermogymnomonas]]''
       }}
    |2={{clade
      |1=''[[Picrophilus]]''
      |2={{clade
        |1=''[[Acidiplasma]]''
        |2=''[[Ferroplasma]]''
         }}
       }}
     }}
   }}
}}
}}
* Family [[Thermoplasmataceae]] <small>Reysenbach 2002</small>
** ''[[Acidiplasma]]'' <small>Golyshina et al. 2009</small>
** ?"''Candidatus'' [[Carboxiplasma]]" <small>Bulaev et al. 2023</small>
** ''[[Cuniculiplasma]]'' <small>corrig. Golyshina et al. 2016</small>
** ''[[Ferroplasma]]'' <small>Golyshina et al. 2000</small>
** ?''[[Oxyplasma]]'' <small>Golyshina et al. 2024</small>
** ''[[Picrophilus]]'' <small>Schleper et al. 1996</small>
** ?"''Candidatus'' [[Scheffleriplasma]]" <small>Krause et al. 2022</small>
** ''[[Thermogymnomonas]]'' <small>Itoh, Yoshikawa & Takashina 2007</small>
** ''[[Thermoplasma]]'' <small>Darland et al. 1970</small>

==Phylum [[Halobacteriota]]==
{{cladogram|title=Phylogeny of Halobacteriota<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|1={{clade
  |1={{clade
  |label1=Methanonatronarchaeia
  |1=[[Methanonatronarchaeales]]
     }}
  |2={{clade
    |1={{clade
      |1={{clade
        |label1="Methanoliparia"
        |1="[[Methanoliparales]]"
        |label2="[[Archaeoglobi|Archaeoglobia]]"
        |2={{clade
          |1="[[Mnemosynellales]]"
          |2=[[Archaeoglobales]]
           }}
         }}
      |2={{clade
        |1={{clade
        |label1="Syntropharchaeia"
        |1={{clade
          |1="[[Syntropharchaeales]]"
          |2="[[Alkanophagales]]"
           }}
           }}
        |2={{clade
          |1={{clade
            |label1=Methanocellia
            |1=[[Methanocellales]]
            |label2=Methanosarcinia
            |2={{clade
              |1=[[Methanotrichales]]
              |2={{clade
                |1=Methanosarcinales_A
                |2=[[Methanosarcinales]]
                 }}
               }}
             }}
           }}
         }}
       }}
    |2={{clade
      |label1="[[Methanomicrobia]]"
      |1=[[Methanomicrobiales]]
      |label2=[[Halobacteria]]
      |2={{clade
        |1=[[Halorutilales]]
        |2=[[Halobacteriales]]
         }}
       }}
     }}
   }}
}}
}}

===Halobacteriota incertae sedis===
* ?"''Candidatus'' [[Methanoinsularis]]" <small>Ou et al. 2022</small>
* ?"''Candidatus'' [[Methanoporticola]]" <small>Ou et al. 2022</small>
====Order "Methanoflorentales"====
* Family "Methanoflorentaceae" <small>Mondav et al. 2014</small>
** ?"''Candidatus'' [[Methanoflorens]]" <small>Mondav et al. 2014</small>

===Class "Methanonatronarchaeia"===
====Order "Methanonatronarchaeales"====
* Family Methanonatronarchaeaceae <small>Sorokin et al. 2018</small>
** "''Candidatus'' [[Methanohalarchaeum]]" <small>Sorokin et al. 2018</small>
** ''[[Methanonatronarchaeum]]'' <small>Sorokin et al. 2018</small>

===Class "Methanoliparia"===
====Order "Methanoliparales"====
* Family "Methanoliparaceae" <small>Borrel et al. 2019</small>
** "''Candidatus'' [[Methanoliparum]]" <small>Borrel et al. 2019</small>
** "''Candidatus'' [[Methanolliviera]]" <small>Borrel et al. 2019</small>

===Class "[[Archaeoglobi|Archaeoglobia]]"===
{{cladogram|title=Phylogeny of "Archaeoglobia"<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:450px
|1={{clade
  |label1="Mnemosynellales"
  |1={{clade
    |label1="Mnemosynellaceae"
    |1="''Candidatus'' [[Mnemosynella]]"
     }}
  |label2=[[Archaeoglobales]]
  |2={{clade
    |label1=[[Archaeoglobaceae]]
    |1={{clade
      |1=''[[Archaeoglobus]]''_A & C
      |2={{clade
        |1={{clade
          |1=''[[Ferroglobus]]''
          |2=''[[Geoglobus]]''
           }}
        |2=''[[Archaeoglobus]]''
         }}
       }}
     }}
   }}
}}
}}
====Order "Mnemosynellales"====
* Family "Mnemosynellaceae" <small>Adam et al. 2022</small>
** "''Candidatus'' [[Mnemosynella]]" <small>Adam et al. 2022</small>

====Order [[Archaeoglobales]]====
* Family "Allopolytropaceae" <small>corrig. Boyd et al. 2019</small>
** ?"''Candidatus'' [[Allopolytropus]]" <small>corrig. Boyd et al. 2019</small> ["''Candidatus'' Polytropus" <small>Boyd et al. 2019 non Kirsch 1866</small>]
* Family [[Archaeoglobaceae]] <small>Huber & Stetter 2002</small>
** ''[[Archaeoglobus]]'' <small>Stetter 1988</small>
** ''[[Ferroglobus]]'' <small>Hafenbradl et al. 1997</small>
** ''[[Geoglobus]]'' <small>Kashefi et al. 2002</small>
** ?"''Candidatus'' [[Methanoglobus]]" <small>Buessecker et al. 2023</small>
** ?"''Candidatus'' [[Methanomixotrophus]]" <small>corrig. Liu et al. 2021</small>
** ?"''Candidatus'' [[Methanoproducendum]]" <small>Hua et al. 2019</small>

===Class "Syntropharchaeia"===
{{cladogram|title=Phylogeny of "Syntropharchaeia"<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:500px
|1={{clade
  |label1="Syntropharchaeales"
  |1={{clade
    |label1="Syntropharchaeaceae"
    |1="''Candidatus'' [[Syntropharchaeum]]"
     }}
  |label2="Alkanophagales"
  |2={{clade
    |label1="Alkanophagaceae"
    |1="''Candidatus'' [[Alkanophaga]]"
    |label2="Methanospiraraceae"
    |2={{clade
      |1="''Candidatus'' [[Methanoxibalbensis]]"
      |2="''Candidatus'' [[Methanospirare]]" 
       }}
     }}
   }}
}}
}}
====Order "Syntropharchaeales"====
* Family "Syntropharchaeaceae" <small>corrig.</small> (ANME-2 cluster)
** "''Candidatus'' [[Syntropharchaeum]]" <small>corrig. Laso-Perez et al. 2016</small>

====Order "Alkanophagales"====
* Family "Methanophagaceae" <small>Chadwick et al. 2022</small>
** ?"''Candidatus'' [[Methanoalium]]" <small>Chadwick et al. 2022</small>
** ?"''Candidatus'' [[Methanophaga]]" <small>Chadwick et al. 2022</small>
* Family ?"Veteromethanophagaceae" <small>Vulcano et al. 2022</small>
* Family "Alkanophagaceae" <small></small> [B39-G2]
** "''Candidatus'' [[Alkanophaga]]" <small>Zehnle et al. 2023</small>
* Family "Methanospiraraceae" <small>Laso-Pérez et al. 2022</small>
** "''Candidatus'' [[Methanospirare]]" <small>Laso-Pérez et al. 2022</small>
** "''Candidatus'' [[Methanoxibalbensis]]" <small>Laso-Pérez et al. 2022</small>

===Class Methanocellia===
====Order Methanocellales====
{{cladogram|title=Phylogeny of Methanocellales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:300px
|label1=Methanocellaceae
|1={{clade
  |1={{clade
    |1=''[[Methanooceanicella]]''
    |2=''[[Methanocella]]''_A
     }}
  |2=''[[Methanocella]]''
   }}
}}
}}
* Family Methanocellaceae <small>Sakai et al. 2008</small>
** ''[[Methanocella]]'' <small>Sakai et al. 2008</small>
** ''[[Methanooceanicella]]'' <small>Zhang et al. 2024</small>

===Class Methanosarcinia===
====Order Methanotrichales====
* Family Methanotrichaceae <small>Akinyemi et al. 2021</small>
** "''Candidatus'' [[Methanocrinis]]" <small>Khomyakova et al. 2023</small>
** ''[[Methanothrix]]'' <small>Huser, Wuhrmann & Zehnder 1983</small> [''[[Methanosaeta]]'' <small>Patel & Sprott 1990</small>]

====Order Methanosarcinales_A====
* Family Methermicoccaceae <small>Cheng et al. 2007</small>
** ''[[Methermicoccus]]'' <small>Cheng et al. 2007</small>

====Order [[Methanosarcinales]]====
{{cladogram|title=Phylogeny of Methanosarcinales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:350px
|1={{clade
  |1={{clade
  |label1="Methanogastraceae"
  |1="''Ca.'' [[Methanogaster]]"
     }}
  |2={{clade
    |1={{clade
      |1={{clade
        |label1="Methanocomedentaceae"
        |1={{clade
          |1="''Ca.'' [[Methanocomedens]]"
          |2="''Ca.'' [[Methanomarinus]]"
           }}
         }}
      |2={{clade
        |label1="Ethanoperedentaceae"
        |1="''Ca.'' [[Ethaniperedens]]"
        |label2="Methanoperedentaceae"
        |2="''Ca.'' [[Methanoperedens]]"
         }}
       }}
    |2={{clade
    |label1=[[Methanosarcinaceae]]
    |1={{clade
      |1={{clade
        |1={{clade
          |1="''[[Methanofrustulum]]''"
          |2={{clade
            |1="''[[Methanolapillus]]''"
            |2=''[[Methanimicrococcus]]''
             }}
           }}
        |2=''[[Methanosarcina]]''
         }}
      |2={{clade
        |1={{clade
          |1=''[[Methanohalobium]]''
          |2=''[[Methanosalsum]]''
           }}
        |2={{clade
          |1={{clade
            |1=''[[Methanococcoides]]''
            |2=''[[Methanohalophilus]]''
             }}
          |2={{clade
            |1=''[[Methanomethylovorans]]''
            |2=''[[Methanolobus]]''
             }}
           }}
         }}
       }}
       }}
     }}
   }}
}}
}}
* Family "Methanogastraceae" <small>corrig. Chadwick et al. 2022</small> (ANME-2c)
** "''Candidatus'' [[Methanogaster]]" <small>Chadwick et al. 2022</small>
* Family "Methanocomedentaceae" <small>corrig. Chadwick et al. 2022</small> 
** "''Candidatus'' [[Methanocomedens]]" <small>Chadwick et al. 2022</small> (ANME-2a)
** "''Candidatus'' [[Methanomarinus]]" <small>Chadwick et al. 2022</small> (ANME-2b)
* Family "Ethanoperedentaceae" <small>(sic) Pallen, Rodriguez-R & Alikhan 2022</small> (EX4572-44)
** "''Candidatus'' [[Ethaniperedens]]" <small>corrig. Hahn et al. 2020</small>
* Family "Methanoperedentaceae" <small>corrig. Haroon et al. 2013</small> 
** "''Candidatus'' [[Methanoperedens]]" <small>Haroon et al. 2013</small> (ANME-2d, AAA)
* Family [[Methanosarcinaceae]] <small>Balch & Wolfe 1981</small>
** ?''[[Halomethanococcus]]'' <small>Yu & Kawamura 1988</small>
** ''[[Methanimicrococcus]]'' <small>corrig. Sprenger et al. 2000</small>
** ''[[Methanococcoides]]'' <small>Sowers & Ferry 1985</small>
** "''[[Methanofrustulum]]''" <small>Protasov & Brune 2023</small>
** ''[[Methanohalobium]]'' <small>Zhilina & Zavarzin 1988</small>
** ''[[Methanohalophilus]]'' <small>Paterek & Smith 1988</small>
** "''[[Methanolapillus]]''" <small>Protasov & Brune 2023</small>
** ''[[Methanolobus]]'' <small>König & Stetter 1983</small>
** ''[[Methanomethylovorans]]'' <small>Lomans et al. 2004</small>
** ''[[Methanosalsum]]'' <small>Boone & Baker 2002</small>
** ''[[Methanosarcina]]'' <small>Kluyver & van Niel 1936</small>
** ?"''Candidatus'' [[Methanovorans]]" <small>Chadwick et al. 2022</small> (ANME-3)

===Class [[Methanomicrobia]]===
====Order [[Methanomicrobiales]]====
{{cladogram|title=Phylogeny of Methanomicrobiales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:350px
|1={{clade
  |1={{clade
    |label1=[[Methanocorpusculaceae]]
    |1={{clade
      |1=''[[Methanocorpusculum]]''
      |2=''[[Methanocalculus]]''
       }}
     }}
  |2={{clade
    |1={{clade
      |label1=Methanofollaceae
      |1=''[[Methanofollis]]''
       }}
    |2={{clade
      |1={{clade
      |label1=[[Methanospirillaceae]]
      |1={{clade
        |1=''[[Methanosphaerula]]''
        |2={{clade
          |1={{clade
            |1=''[[Methanolinea]]''
            |2=''[[Methanoregula]]''
             }}
          |2={{clade
            |1="''[[Methanofilum]]''"
            |2=''[[Methanospirillum]]''
             }}
           }}
         }}
         }}
      |2={{clade
        |label1=Methanoculleaceae
        |1=''[[Methanoculleus]]''
        |label2=[[Methanomicrobiaceae]]
        |2={{clade
          |1={{clade
            |1=''[[Methanovulcanius]]''
            |2=''[[Methanogenium]]''
             }}
          |2={{clade
            |1=''[[Methanoplanus]]''
            |2={{clade
              |1=''[[Methanomicrobium]]''
              |2=''[[Methanolacinia]]''
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}
* Family [[Methanocorpusculaceae]] <small>Zellner et al. 1989</small>
** ''[[Methanocalculus]]'' <small>Ollivier et al. 1998 </small>
** ''[[Methanocorpusculum]]'' <small>Zellner et al. 1988</small> ["''[[Methanorbis]]''" <small>Protasov & Brune 2023</small>]
* Family Methanofollaceae <small>Chuvochina et al. 2024</small>
** ''[[Methanofollis]]'' <small>Zellner et al. 1999</small>
* Family [[Methanospirillaceae]] <small>Boone et al. 2002</small>
** "''[[Methanofilum]]''" <small>Protasov & Brune 2023</small>
** ''[[Methanolinea]]'' <small>Imachi et al. 2008</small>
** ''[[Methanoregula]]'' <small>Brauer et al. 2011</small>
** ''[[Methanosphaerula]]'' <small>Cadillo-Quiroz et al. 2009</small>
** ''[[Methanospirillum]]'' <small>Ferry, Smith & Wolfe 1974</small>
* Family Methanoculleaceae <small>Chuvochina et al. 2024</small>
** ''[[Methanoculleus]]'' <small>Maestrojun et al. 1990</small>
* Family [[Methanomicrobiaceae]] <small>Balch & Wolfe 1981</small>
** ?''[[Methanochimaera]]'' <small>Zhou et al. 2024</small>
** ''[[Methanogenium]]'' <small>Romesser et al. 1981</small>
** ''[[Methanolacinia]]'' <small>Zellner et al. 1990</small>
** ''[[Methanomicrobium]]'' <small>Balch & Wolfe 1981</small>
** ''[[Methanoplanus]]'' <small>Wildgruber et al. 1984</small>
** ''[[Methanovulcanius]]'' <small>Chien et al. 2023</small>

===Class "Hikarchaeia"===
====Order "Hikarchaeales"====
* Family "Hikarchaeaceae" <small>Martijn et al. 2020</small> (MG-IV)
** ?"''Candidatus'' [[Hikarchaeum]]" <small>Martijn et al. 2020</small>

===Class "Ordosarchaeia"===
====Order "Ordosarchaeales"====
* Family "Ordosarchaeaceae" <small>Zhao et al. 2024</small>
** ?"''Candidatus'' [[Ordosarchaeum]]" <small>Zhao et al. 2024</small>

===Class [[Halobacteria]]===
====Order Halorutilales====
* Family Halorutilaceae <small>Durán-Viseras et al. 2023</small>
** "''Candidatus'' [[Afararchaeum]]" <small>Baker et al. 2024</small>
** ''[[Halorutilus]]'' <small>Durán-Viseras et al. 2023</small>

====Order [[Halobacteriales]]====
{{cladogram|title=Phylogeny of Halobacteriales<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{clade
  |1={{clade
    |label1="Chewarchaeaceae"
    |1="''Candidatus'' [[Chewarchaeum]]"
     }}
  |2={{clade
    |1={{clade
      |label1="Halalkalicoccaceae"
      |1=''[[Halalkalicoccus]]''
       }}
    |2={{clade
      |1={{clade
        |1={{clade
          |1={{clade
            |label1="Salinarchaeaceae"
            |1=''[[Salinarchaeum]]''
            }}
          |2={{clade
            |label1="Halostellaceae"
            |1=''[[Halostella]]''
            |label2=Natronoarchaeaceae
            |2={{clade
              |1=''[[Natranaeroarchaeum]]''
              |2=''[[Natronoarchaeum]]''
               }}
             }}
           }}
        |2=[[Natrialbaceae]] cont'd
         }}
      |2={{clade
        |1={{clade
          |label1=Haladaptataceae 
          |1={{clade
            |1={{clade
              |1=''[[Halomicrococcus]]''
              |2=''[[Haladaptatus]]''
               }}
            |2=''[[Halorussus]]''
             }}
          |label2=[[Halobacteriaceae]]
          |2={{clade
            |1={{clade
              |1=''[[Halanaeroarchaeum]]''
              |2=''[[Halodesulfurarchaeum]]''
               }}
            |2={{clade
              |1={{clade
                |1={{clade
                  |1=''[[Halospeciosus]]''
                  |2=''[[Salarchaeum]]''
                   }}
                |2={{clade
                  |1=''[[Halocalculus]]''
                  |2=''[[Halarchaeum]]''
                   }}
                 }}
              |2=''[[Halobacterium]]''
               }}
             }}
           }}
        |2={{clade
          |1={{clade
            |label1=[[Halococcaceae]]
            |1=''[[Halococcus]]''
            |label2=[[Haloarculaceae]]
            |2={{clade
              |1={{clade
                |1={{clade
                  |1=''[[Halocatena]]''
                  |2=''[[Halomarina]]''
                   }}
                |2={{clade
                  |1=''[[Natronomonas]]''
                  |2={{clade
                    |1={{clade
                      |1=''[[Halorarius]]''
                      |2=''[[Halosegnis]]''
                       }}
                    |2={{clade
                      |1=''[[Salinirubellus]]''
                      |2=''[[Haloglomus]]''
                       }}
                     }}
                   }}
                 }}
              |2={{clade
                |1=''[[Halorientalis]]''
                |2={{clade
                  |1={{clade
                    |1={{clade
                      |1=''[[Halapricum]]''
                      |2={{clade
                        |1=''[[Halococcoides]]''
                        |2=''[[Halorhabdus]]''
                         }}
                       }}
                    |2={{clade
                      |1={{clade
                        |1=''[[Salinirussus]]''
                        |2={{clade
                          |1=''[[Salinibaculum]]''
                          |2=''[[Halovenus]]''
                           }}
                         }}
                      |2=''[[Halosimplex]]''
                       }}
                     }}
                  |2={{clade
                    |1=''[[Halomicrobium]]''
                    |2=''[[Haloarcula]]''
                     }}
                   }}
                 }}
               }}
             }}
          |2=[[Haloferacaceae]] cont'd
           }}
         }}
       }}
     }}
   }}
}}
}}

* Halobacteriales incertae sedis
** "''[[Haloalcalophilium]]''" <small>Lizama et al. 2000a</small>
* Family "Chewarchaeaceae" <small>Baker et al. 2024</small>
** "''Candidatus'' [[Chewarchaeum]]" <small>Baker et al. 2024</small>
* Family "Halalkalicoccaceae" <small>Mao et al. 2025</small>
** ''[[Halalkalicoccus]]'' <small>Xue et al. 2005</small>
** ?"''[[Natronorarus]]''" <small>Mao et al. 2025</small>
* Family "Salinarchaeaceae" <small></small>
** ''[[Salinarchaeum]]'' <small>Cui et al. 2014</small>
* Family "Halostellaceae" <small>Pallen, Rodriguez-R & Alikhan 2022</small>
** ''[[Halostella]]'' <small>Song et al. 2016</small>
* Family Natronoarchaeaceae <small>Sorokin et al. 2023</small>
** "''[[Natranaeroarchaeum]]''" <small>Sorokin et al. 2021</small>
** ''[[Natronoarchaeum]]'' <small>Shimane et al. 2010</small>
{{cladogram|title=Phylogeny of Natrialbaceae<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{clade
  |1={{clade
    |1=''[[Halorubellus]]''
    |2=''[[Haloarchaeobius]]''
     }}
  |2={{clade
    |1=''[[Halovivax]]''
    |2={{clade
      |1={{clade
        |1="''[[Salinilacihabitans]]''"
        |2={{clade
          |1="''[[Natronobeatus]]''"
          |2=''[[Natribaculum]]''
           }}
         }}
      |2={{clade
        |1={{clade
          |1={{clade
            |1=''[[Saliphagus]]''
            |2={{clade
              |1=''[[Natronobiforma]]''
              |2="''[[Halomontanus]]''"
               }}
             }}
          |2={{clade
            |1="''[[Natrononativus]]''"
            |2=''[[Natronosalvus]]''
             }}
           }}
        |2={{clade
          |1=''[[Halostagnicola]]''
          |2={{clade
            |1=''[[Halosolutus]]''
            |2={{clade
              |1={{clade
                |1={{clade
                  |1=''[[Halopiger goleimassiliensis]]''
                  |2=''[[Natrarchaeobaculum]]''
                   }}
                |2={{clade
                  |1=''[[Salinadaptatus]]''
                  |2=''[[Natrarchaeobius]]''
                   }}
                 }}
              |2={{clade
                |1=''[[Natronococcus]]''
                |2={{clade
                  |1={{clade
                    |1={{clade
                      |1=''[[Halopiger]]''
                      |2={{clade
                        |1=''[[Halopiger djelfimassiliensis]]''
                        |2={{clade
                          |1=''[[Natronobacterium]]''
                          |2=''[[Halobiforma]]''
                           }}
                         }}
                       }}
                    |2={{clade
                      |1=''[[Natronolimnobius]]''
                      |2=''[[Natrialba]]''
                       }}
                     }}
                  |2={{clade
                    |1={{clade
                      |1={{clade
                        |1=''[[Natronolimnohabitans]]''
                        |2=''[[Haloterrigena]]''
                         }}
                      |2=''[[Natronorubrum]]''
                       }}
                    |2=''[[Natrinema]]''
                     }}
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}
* Family [[Natrialbaceae]] <small>Gupta et al. 2015</small>
** ''[[Haloarchaeobius]]'' <small>Makhdoumi-Kakhki et al. 2012</small>
** ''[[Halobiforma]]'' <small>Hezayen et al. 2002</small>
** "''[[Halomontanus]]''" <small>Mao et al. 2024</small> [''[[Natronoglomus]]'' <small>Sorokin et al. 2025</small>]
** ''[[Halopiger]]'' <small>Gutierrez et al. 2007</small>
** ''[[Halorubellus]]'' <small>Cui et al. 2014</small>
** ''[[Halosolutus]]'' <small>Sun et al. 2022</small>
** ''[[Halostagnicola]]'' <small>Castillo et al. 2006</small>
** ''[[Haloterrigena]]'' <small>Ventosa et al. 1999</small>
** ?''[[Halovalidus]]'' <small>Dong et al. 2025</small>
** ''[[Halovivax]]'' <small>Castillo et al. 2006</small>
** ''[[Natrarchaeobaculum]]'' <small>Sorokin et al. 2020</small>
** ''[[Natrarchaeobius]]'' <small>corrig. Sorokin et al. 2020</small>
** ''[[Natrialba]]'' <small>Kamekura & Dyall-Smith 1996</small>
** ''[[Natribaculum]]'' <small>Liu et al. 2015 </small> [''Halovarius'' <small>Mehrshad et al. 2015</small>]
** ''[[Natronobacterium]]'' <small>Tindall et al. 1984</small>
** ''[[Natronobiforma]]'' <small>Sorokin et al. 2019</small>
** ''[[Natronococcus]]'' <small>Tindall et al. 1984</small>
** ''[[Natronolimnobius]]'' <small>Itoh et al. 2005</small>
** ''[[Natronolimnohabitans]]'' <small>Sorokin et al. 2020</small>
** ''[[Natrinema]]'' <small>McGenity et al. 1998</small>
** "''[[Natronobeatus]]''" <small>Li et al. 2023</small>
** "''[[Natrononativus]]''" <small>Li et al. 2023</small>
** ''[[Natronorubrum]]'' <small>Xu et al. 1999</small>
** ''[[Natronosalvus]]'' <small>Tan et al. 2023</small>
** ''[[Salinadaptatus]]'' <small>Xue et al. 2020 </small>
** "''[[Salinilacihabitans]]''" <small>Li et al. 2023</small>
** ''[[Saliphagus]]'' <small>Yin et al. 2017</small>
* Family Haladaptataceae <small>Rinke et al. 2020</small>
** ''[[Haladaptatus]]'' <small>Savage et al. 2007</small>
** ''[[Halomicrococcus]]'' <small>Chen et al. 2020</small>
** ''[[Halorussus]]'' <small>Cui et al. 2014</small>
* Family [[Halococcaceae]] <small>Gupta et al. 2016</small>
** ''[[Halococcus]]'' <small>Schoop 1935</small>
* Family [[Haloarculaceae]] <small></small>
** ''[[Halapricum]]'' <small>Song et al. 2014</small>
** ''[[Haloarcula]]'' <small>Torreblanca et al. 1986</small> [''[[Halomicrobium]]'' <small>Oren et al. 2002</small>; ''Halosiccatus'' <small>Mehrshad et al. 2016</small>]
** ''[[Halocatena]]'' <small>Verma et al. 2020</small>
** ''[[Halococcoides]]'' <small>Sorokin et al. 2019</small>
** ''[[Haloglomus]]'' <small>Duran-Viseras, Sanchez-Porro & Ventosa 2020</small>
** ''[[Halomarina]]'' <small>Inoue et al. 2011</small>
** ''[[Halomicroarcula]]'' <small>Echigo et al. 2013</small>
** ''[[Halorientalis]]'' <small>Cui et al. 2011</small>
** ''[[Halorarius]]'' <small>Sun et al. 2023</small>
** ''[[Halorhabdus]]'' <small>Waino et al. 2000</small>
** ''[[Halosegnis]]'' <small>Duran-Viseras et al. 2022</small> [''Sala'' <small>Song et al. 2023 non Ross 1937 non Walker 1867</small>; ''Salella'' <small>Deshmukh & Oren 2023</small>]
** ''[[Halosimplex]]'' <small>Vreeland et al. 2003</small>
** ''[[Halovenus]]'' <small>Makhdoumi-Kakhki et al. 2012</small>
** ''[[Natronomonas]]'' <small>Kamekura et al. 1997</small>
** ''[[Salinibaculum]]'' <small>Han & Cui 2020</small>
** ''[[Salinirubellus]]'' <small>Hou et al. 2018</small>
** ''[[Salinirussus]]'' <small>Cui et al. 2017</small>
* Family [[Halobacteriaceae]] <small></small>
** ''[[Halanaeroarchaeum]]'' <small>Sorokin et al. 2016</small>
** ''[[Halarchaeum]]'' <small>Minegishi et al. 2010</small>
** ''[[Halobacterium]]'' <small>(Elazari-Volcani 1940) Elazari-Volcani 1957</small> ["''Halobacter''" <small>Anderson 1954</small>]
** ''[[Halocalculus]]'' <small>Minegishi et al. 2015</small>
** ''[[Halodesulfurarchaeum]]'' <small>Sorokin et al. 2017</small>
** ''[[Halospeciosus]]'' <small>Li et al. 2024</small>
** ''[[Salarchaeum]]'' <small>Shimane et al. 2011</small>
{{cladogram|title=Phylogeny of Haloferacaceae<ref name="about" /><ref name="tree" /><ref name="taxon_history" />|
{{clade|style=font-size:90%;line-height:90%;width:400px
|1={{clade
  |1=''[[Salinirubrum]]''
  |2={{clade
    |1={{clade
      |1=''[[Haloplanus]]''
      |2={{clade
        |1={{clade
          |1=''[[Halobium]]''
          |2={{clade
            |1=''[[Halegenticoccus]]''
            |2={{clade
              |1=''[[Halogranum]]''
              |2=''[[Haloprofundus]]''
               }}
             }}
           }}
        |2={{clade
          |1=''[[Salinigranum]]''
          |2={{clade
            |1=''[[Haloferax]]''
            |2={{clade
              |1=''[[Halopelagius]]''
              |2={{clade
                |1=''[[Halogeometricum]]''
                |2={{clade
                  |1=''[[Haloquadratum]]''
                  |2=''[[Halobellus]]''
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
    |2={{clade
      |1={{clade
        |1={{clade
          |1=''[[Halalkalirubrum]]''
          |2=''[[Natronocalculus]]''
           }}
        |2={{clade
          |1=''[[Halohasta]]''
          |2=''[[Halonotius]]''
           }}
         }}
      |2={{clade
        |1={{clade
          |1=''[[Halolamina]]''
          |2={{clade
            |1=''[[Halorarum]]''
            |2=''[[Halobaculum]]''
             }}
           }}
        |2={{clade
          |1=''[[Halalkaliarchaeum]]''
           |2={{clade
            |1=''[[Halopenitus]]''
            |2={{clade
              |1=''[[Haloparvum]]''
              |2=''[[Halorubrum]]''
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}
* Family [[Haloferacaceae]] <small>Gupta et al. 2015</small>
** ''[[Halalkaliarchaeum]]'' <small>Sorokin et al. 2019</small>
** ''[[Halalkalirubrum]]'' <small>Zuo et al. 2021</small>
** ?"''Candidatus'' [[Halectosymbiota]]" <small>corrig. Filker et al. 2014</small>
** ''[[Halegenticoccus]]'' <small>Liu et al. 2022</small>
** ''[[Halobaculum]]'' <small>Oren et al. 1995</small> ["''Candidatus'' Halobonum" <small>Ugalde et al. 2013</small>]
** ''[[Halobellus]]'' <small>Cui et al. 2011</small>
** ''[[Halobium]]'' <small>Mori et al. 2016</small>
** ''[[Haloferax]]'' <small>Torreblanca et al. 1986</small>
** ''[[Halogeometricum]]'' <small>Montalvo-Rodriguez et al. 1998</small> [''[[Halosarcina]]'' <small>Savage et al. 2008</small>]
** ''[[Halogranum]]'' <small>Cui et al. 2010</small>
** ''[[Halohasta]]'' <small>Mou et al. 2013</small>
** ''[[Halolamina]]'' <small>Cui et al. 2011</small>
** ''[[Halonotius]]'' <small>Burns et al. 2010</small>
** ''[[Haloparvum]]'' <small>Chen et al. 2016</small>
** ''[[Halopelagius]]'' <small>Cui et al. 2010</small>
** ''[[Halopenitus]]'' <small>Amoozegar et al. 2012</small>
** ''[[Haloplanus]]'' <small>Elevi Bardavid et al. 2007</small>
** ''[[Haloprofundus]]'' <small>Zhang et al. 2017</small>
** ''[[Haloquadratum]]'' <small>Burns et al. 2007</small>
** ''[[Halorubrum]]'' <small>McGenity & Grant 1996</small> [''Halorubrobacterium'' <small>Kamekura & Dyall-Smith 1996</small>]
** ''[[Natronocalculus]]'' <small>Sorokin et al. 2023</small>
** ?''[[Salinirarus]]'' <small>Zhang et al. 2025</small>
** ''[[Salinirubrum]]'' <small>corrig. Cui & Qiu 2014</small>
** ''[[Salinigranum]]'' <small>Cui & Zhang 2014</small>

==See also==
* [[Branching order of bacterial phyla (Woese, 1987)]]
* [[Branching order of bacterial phyla (Gupta, 2001)]]
* [[Branching order of bacterial phyla (Cavalier-Smith, 2002)]]
* [[Branching order of bacterial phyla (Rappe and Giovanoni, 2003)]]
* [[Branching order of bacterial phyla (Battistuzzi et al.,2004)]]
* [[Branching order of bacterial phyla (Ciccarelli et al., 2006)]]
* [[Branching order of bacterial phyla after ARB Silva Living Tree]]
* [[Branching order of bacterial phyla (Genome Taxonomy Database, 2018)]]
* [[Bacterial phyla]]
* [[List of bacteria genera]]
* [[List of bacterial orders]]

== References ==
{{reflist}}

{{Archaea classification}}
[[Category:Archaea genera| ]]
[[Category:Taxonomic lists (genera, taxonomic)|Archaea]]