List of Archaea genera

This article lists the genera of the Archaea and also shows taxa of archaea that do not contain genera. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) unless otherwise noted.

Phylogeny

For the GTDB 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.

Cladogram was taken from the GTDB release 10-RS226 (16 April 2025).

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> [CSSED10-239]
• "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"

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 "Aenigmatarchaeota"

Class "Aenigmatarchaeia"

Order "Aenigmatarchaeales"

• Family "Aenigmatarchaeaceae" <small>corrig. Rinke et al. 2020</small>
• "Candidatus Aenigmatarchaeum" <small>corrig. Rinke et al. 2013</small>

Phylum "Nanohalarchaeota"

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 Nanobdellota

Class Nanobdellia

Order "Pacearchaeales"

Order "Woesearchaeales"

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> ["Ca. Nanobsidianus" <small>Castelle et al. 2015</small>; "Ca. 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 "Jingweiarchaeales"

• Family "Jingweiarchaeaceae" <small>Rao et al. 2023</small>
• "Candidatus Jingweiarchaeum" <small>Rao et al. 2023</small>

Order JAPDLS01

• Family "Haiyanarchaeaceae" <small>Rao et al. 2023</small>
• "Candidatus Haiyanarchaeum" <small>Rao et al. 2023</small> ["Ca. Tinosarcha" <small>Pallen, Rodriguez-R & Alikhan 2022</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 Promethearchaeota

Taxonomy of this group is based on LPSN, and also these works:

Promethearchaeota incertae sedis

• ?"Friggarchaeota" <small>Caceres 2019</small>
• ?"Gefionarchaeota" <small>Caceres 2019</small>
• ?"Idunnarchaeota" <small>Caceres 2019</small>
• ?"Sleipnirarchaeota" <small>Kioukis et al. 2025</small>
• ?"Candidatus Balderarchaeum" <small>Xie et al. 2022</small>
• ?"Candidatus Sukunaarchaeum" <small>Harada et al. 2025</small>
• ?"Candidatus Tyrarchaeum" <small>Xie et al. 2022</small>

Class "Asgardarchaeia"

Order "Asgardarchaeales"

• Family "Asgardarchaeaceae" <small> Eme et al. 2023 ex Tamarit et al. 2024</small>
• "Candidatus Asgardarchaeum" <small>Eme et al. 2023 ex Tamarit et al. 2024</small>

Class "Atabeyarchaeia"

Order "Atabeyarchaeales"

• Family "Atabeyarchaeaceae" <small> Valentin-Alvaradoet al. 2024</small>
• "Candidatus Atabeyarchaeum" <small>Valentin-Alvarado et al. 2024</small>

Class "Sifarchaeia"

Order "Sifarchaeales"

• Family "Sifarchaeaceae" <small>Sun et al. 2021</small>
• "Candidatus Sifarchaeum" <small>corrig. Farag, Zhao & Biddle 2020</small>

Order "Borrarchaeales"

• Family "Borrarchaeaceae" <small>Liu et al. 2021</small>
• "Candidatus Borrarchaeum" <small>Liu et al. 2021</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 "Panguiarchaeaceae" <small>Qu et al. 2023</small>
• "Panguiarchaeum" <small>Qu et al. 2023</small>
• Family "Njordarchaeaceae" <small>Xie et al. 2022</small>
• "Candidatus Njordarchaeum" <small>Xie et al. 2022</small>

Class "Heimdallarchaeia"

Order "Wenzhongarchaeales"

Order "Hodarchaeales"

• Family "Hodarchaeaceae" <small>Liu et al. 2021</small>
• "Candidatus Hodarchaeum" <small>Liu et al. 2021</small>
• Family "Margulisarchaeaceae" <small>Imachi et al. 2025</small>
• ?"Candidatus Flexarchaeum" <small>Imachi et al. 2025</small>
• ?"Candidatus Margulisarchaeum" <small>Imachi et al. 2025</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>

Class "Odinarchaeia"

Order "Odinarchaeales"

• Family "Odinarchaeaceae" <small>Tamarit et al. 2022</small>
• "Candidatus Odinarchaeum" <small>Tamarit et al. 2022</small>

Order "Yangjianarchaeales"

Class "Jordarchaeia"

Order "Jordarchaeales"

• Family "Freyrarchaeaceae" <small>Xie et al. 2022</small>
• "Candidatus Freyrarchaeum" <small>Xie et al. 2022</small>
• Family "Jordarchaeaceae" <small>Sun et al. 2021</small>
• "Candidatus Jordarchaeum" <small>Sun et al. 2021</small> ["Ca. Freyarchaeum" <small>(sic) Valentin-Alvarado et al. 2024</small>]

Class "Baldrarchaeia"

Order "Baldrarchaeales"

• Family "Baldrarchaeaceae" <small>corrig. Liu et al. 2021</small>
• "Candidatus Baldrarchaeum" <small>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>Liu et al. 2021</small>

Class Promethearchaeia

Order "Helarchaeales"

Order Promethearchaeales

• Family Sigynarchaeaceae <small>Xie et al. 2022</small>
• "Candidatus Sigynarchaeum" <small>Xie et al. 2022</small>
• Family Promethearchaeaceae <small>Imachi et al. 2024</small>
• "Candidatus Harpocratesius" <small>Wu et al. 2022</small>
• "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

Thermoproteota Incertae sedis

"Brockiarchaeota"

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"

• Family "Hecatellaceae" <small>Rinke et al. 2020</small>
• "Candidatus Hecatella" <small>Adam et al. 2022</small>
• "Candidatus Jinwuarcula" <small>Hou et al. 2023</small> [B25]
• "Candidatus Jinwuicola" <small>Hou et al. 2023</small> [EX4484-218 sp002254975]
• ?"Candidatus Jinwuimonas" <small>Hou et al. 2023</small>
• "Candidatus Jinwuimorpha" <small>Hou et al. 2023</small> [EX4484-218 sp003661965]
• ?"Candidatus Jinwuiprofundus" <small>Hou et al. 2023</small>
• ?"Candidatus Jinwuousia" <small>Hou et al. 2023</small> [JdFR-11 sp002011035]

Order "Houtuarculales"

• 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 Houtuousia" <small>Hou et al. 2023</small> [40CM-2-53-6]
• Family "Houtuarculaceae" <small>Hou et al. 2023</small>
• ?"Candidatus Limnohoutuiplasma" <small>Hou et al. 2023</small>
• "Candidatus Houtuarcula" <small>Hou et al. 2023</small> [FEN-987]

Order "Wuzhiqiibiales"

• 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"

• 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 Fufeiimorpha" <small>Hou et al. 2023</small> [PIYB01]
• "Candidatus Hanbarchaeum" <small>Hou et al. 2023</small> [DTEX01]
• "Candidatus Zhurongicella" <small>Hou et al. 2023</small> [B63]
• Family "Marizhurongicellaceae" <small>Hou et al. 2023</small> [B26-1]
• ?"Candidatus Aoguangisoma" <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]
• ?"Candidatus Yanziimonas" <small>Hou et al. 2023</small>
• ?"Candidatus Zhurongibium" <small>Hou et al. 2023</small>
• 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 Baizobellus" <small>Hou et al. 2023</small> [SOJZ01]
• ?"Candidatus Baizosediminiarchaeum" <small>Yu et al. 2023</small> [BIN-L-1]
• "Candidatus Baizosoma" <small>Hou et al. 2023</small> [BA1 sp001399805]
• ?"Candidatus Baizostella" <small>Hou et al. 2023</small>
• "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> ["Ca. Hafrusarcha" <small>Pallen, Rodriguez-R & Alikhan 2022</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 Nitrososphaeria_A

Order "Caldarchaeales"

• 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> ["Ca. Cadrafarcha" <small>Pallen, Rodriguez-R & Alikhan 2022</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 Nitrososphaeria

Nitrososphaeria incertae sedis

• ?"Candidatus 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 "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

• 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 Gagatemarchaeum" <small>Sheridan et al. 2023</small> [Bog-1369; GCA_003164815.1]
• ?"Candidatus Subgagatemarchaeum" <small>Sheridan et al. 2023</small> [Fn1; IMG2558309099]
• 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 "Nitrosomiraceae" <small>Zheng et al. 2024</small>
• "Candidatus Nitrosomirus" <small>Zheng et al. 2024</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> ["Ca. Flebogarcha" <small>Pallen, Rodriguez-R & Alikhan 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 Nitrosoabyssus" <small>Garritano et al. 2024</small>
• ?"Candidatus Nitrosokoinonia" <small>Glasl et al. 2023</small>
• "Candidatus Nitrosomaritimum" <small>Zhao et al. 2024</small>
• "Candidatus Nitrosopelagicus" <small>Santoro et al. 2015</small>
• Nitrosopumilus <small>Qin et al. 2017</small> ["Ca. 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"

• 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> ["Ca. Methanomedium" <small>Berghuis et al. 2019</small>]
• Family "Culexmicrobiaceae" <small>Kohtz et al. 2022</small>
• "Candidatus Culexmicrobium" <small>Kohtz et al. 2022</small>

Order "Methanosuratincolales"

• Family "Candidatus Methanosuratincolaceae" <small>Wu et al. 2025</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 Thermoproteia

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

• 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 "Tardisphaerales"

• Family "Marsarchaeaceae" (sic) (NAG2, NCGII)
• Family "Tardisphaerace" <small>Prokofeva et al. 2025</small>
• ?"Tardisphaera" <small>Prokofeva et al. 2025</small>

Order Sulfolobales

• Family Desulfurococcaceae <small>Zillig & Stetter 1983</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 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> ["Ca. Hestiella" <small>St-John and Reysenbach 2024</small>]
• "Candidatus Calypsonella" <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 Ignicoccaceae <small>Chuvochina et al. 2024</small>
• Ignicoccus <small>Huber, Burggraf & Stetter 2000</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>
• ?"Caldariella" <small>de Rosa, Gambacorta & Bu'lock 1975</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

Class "Theionarchaeia"

Class Thermococci

Order "Methanofastidiosales"

• Family "Methanofastidiosaceae" <small>Rinke et al. 2020</small>
• "Candidatus Methanofastidiosum" <small>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> ["Caldococcus" <small>Svetlichny et al. 1987</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

Class "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 Methanopyria

Order Methanopyrales

• Family Methanopyraceae <small>Huber & Stetter 2002</small>
• Methanopyrus <small>Kurr et al. 1992</small>

Class Methanobacteriia

Order Methanobacteriales

• 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

Class "Izemarchaea"

Order "Thermoprofundales"

• (MBG-D, E2)

Class "Poseidoniia"

Order MGIII

Order "Poseidoniales"

• Family "Poseidoniaceae" <small>Rinke et al. 2019</small>
• "Candidatus Poseidonia" <small>Rinke et al. 2019</small>
• Family "Thalassarchaeaceae" <small>Rinke et al. 2019</small>
• "Candidatus Thalassarchaeum" <small>corrig. Martin-Cuadrado et al. 2015</small>

Class "Penumbrarchaeia"

Order "Penumbrarchaeales"

• Family "Penumbrarchaeaceae" <small>Maeke et al. 2025</small>
• "Candidatus Penumbrarchaeum" <small>Maeke et al. 2025</small> [EX4484-36: EX4484-36: EX4484-6: GCA_965234725.1]

Class Thermoplasmata

Order "Angelarchaeales"

Order "Lunaplasmatales"

• Family "Lunaplasmataceae" <small>corrig. Zinke et al. 2021</small>
• ?"Candidatus Lunaplasma" <small>(sic) Zinke et al. 2021</small>

Order "Proteinoplasmatales"

• (SG8-5)

Order "Yaplasmatales"

• (RBG-16-68-12) [incl. "Detorarchales" <small>Pallen & Alikhan 2021</small>; "Limitiplasmatales" <small>corrig. Zheng et al. 2022</small>]

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

• 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>Borrel et al. 2024</small>
• "Candidatus Methanomicula" <small>Protasov & Brune 2023</small> ["Ca. Cribefarcha" <small>Pallen, Rodriguez-R & Alikhan 2022</small>]
• "Methanoplasma" <small>Lang & Brune 2023</small>
• "Methanoprimaticola" <small>Chibani et al. 2023</small>
• ?"Candidatus Methanospyradousia" <small>Gilroy et al. 2021</small>

Order "Halarchaeoplasmatales"

• 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> ["Ca. 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

• 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

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 "Archaeoglobia"

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> ["Ca. 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"

Order "Aerarchaeales"

• Family YL-1
• "Candidatus Methanodefluvium" <small>Leu et al. 2025</small>
• Family "Aerarchaeaceae" <small>Leu et al. 2025</small> [CG-2]
• "Candidatus Aerarchaeum" <small>Leu et al. 2025</small> (GG-2)
• "Candidatus Aerovita" <small>Leu et al. 2025</small> (CM-1, CG-1, MW-1)

Order "Syntropharchaeales"

• Family "Syntropharchaeaceae" (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" [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

• 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

• 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> ["Ca. Argarchaeum" <small>corrig. Chen et al. 2019</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 2025</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

• 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> [Methanoeremita <small>Zhou et al. 2024</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

• ?"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"
• 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. 2023</small>
• Natronoarchaeum <small>Shimane et al. 2010</small>

• 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 Halobacteriaceae
• 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>
• Family Halococcaceae <small>Gupta et al. 2016</small>
• Halococcus <small>Schoop 1935</small>
• Family Haloarculaceae
• Halapricum <small>Song et al. 2014</small> ["Halarchaeoglobus" <small>Sorokin et al. 2021</small>]
• Haloarcula <small>Torreblanca et al. 1986</small> [Halomicroarcula <small>Echigo et al. 2013</small>]
• Halocatena <small>Verma et al. 2020</small> [Actinarchaeum <small>corrig. Tang et al. 2024</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>
• Halomicrobium <small>Oren et al. 2002</small> [Halosiccatus <small>Mehrshad et al. 2016</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 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