List of Archaea genera

Phylogeny

Phylum [Microcaldota]

Class Microcaldia

Order Microcaldales

• Family Microcaldaceae Sakai et al. 2023
• * Microcaldus Sakai et al. 2023

  Phylum "[Altarchaeota]"

Class "Altarchaeia"

Order "Altarchaeales"

• Family "Altarchaeaceae" corrig. Probst et al. 2014
• * "Candidatus Altarchaeum" corrig. Probst et al. 2014

  Phylum "[Iainarchaeota]"

Class "Iainarchaeia"

Order "Forterreales"

• Family "Forterreaceae" Pallen, Rodriguez-R & Alikhan 2022
• * "Candidatus Forterrea" Probst & Banfield 2017

  Order "Iainarchaeales"

• Family "Iainarchaeaceae" Rinke et al. 2020
• * "Candidatus Iainarchaeum" Rinke et al. 2013

  Phylum "[Micrarchaeota]"

Class "Micrarchaeia"

Order "Norongarragalinales"

• Family "Norongarragalinaceae" Vázquez-Campos et al. 2021
• * "Candidatus Norongarragalina" Vázquez-Campos et al. 2021

  Order "Micrarchaeales"

• Family "Micrarchaeaceae" Vázquez-Campos et al. 2021
• * "Candidatus Mancarchaeum" Golyshina et al. 2017
• * "Candidatus Micrarchaeum" Baker et al. 2010

  Order "Anstonellales"

• Family "Anstonellaceae" Vázquez-Campos et al. 2021
• * "Candidatus Anstonella" Vázquez-Campos et al. 2021
• Family "Bilamarchaeaceae" Vázquez-Campos et al. 2021
• * "Candidatus Bilamarchaeum" Vázquez-Campos et al. 2021

  Order "Gugararchaeales"

• Family "Gugararchaeaceae" Vázquez-Campos et al. 2021
• * "Candidatus Gugararchaeum" Vázquez-Campos et al. 2021

  Order "Burarchaeales"

• Family "Burarchaeaceae" Vázquez-Campos et al. 2021
• * "Candidatus Burarchaeum" Vázquez-Campos et al. 2021

  Order "Fermentimicrarchaeales"

• Family "Fermentimicrarchaeaceae" Kadnikov et al. 2020
• * "Candidatus Fermentimicrarchaeum" Kadnikov et al. 2020

  Phylum "[Undinarchaeota]"

Class "Undinarchaeia"

Order "Undinarchaeales"

• Family "Naiadarchaeaceae" Dombrowski et al. 2020
• * "Candidatus Naiadarchaeum" Dombrowski et al. 2020
• Family "Undinarchaeaceae" Dombrowski et al. 2020
• * "Candidatus Undinarchaeum" Dombrowski et al. 2020

  Phylum "[Huberarchaeaota]"

Class "Huberarchaeia"

Order "Huberarchaeales"

• Family "Huberarchaeaceae" Rinke et al. 2020
• * "Candidatus Huberarchaeum" corrig. Schwank et al. 2019

  Phylum "Aenigmatarchaeota">Aenigmarchaeota">Aenigmatarchaeota"

Class "Aenigmatarchaeia"

Order "Aenigmatarchaeales"

• Family "Aenigmatarchaeaceae" corrig. Rinke et al. 2020
• * "Candidatus Aenigmatarchaeum" corrig. Rinke et al. 2013

  Phylum "Nanohalarchaeota">Nanohaloarchaeota">Nanohalarchaeota"

Class "Nanohalarchaeia"

Order "Nanohalarchaeales"

• Family "Nanohalarchaeaceae"
• * ?"Candidatus Nanohalarchaeum" corrig. Hamm et al. 2019
• * ?"Candidatus Nanopetraeus" corrig. Crits‐Christoph et al. 2016

  Order "Nanohydrothermales"

• Family "Nanohydrothermaceae" Xie et al. 2022
• * ?"Candidatus Nanohydrothermus" Xie et al. 2022

  Order "Nucleotidisoterales"

• Family "Nanosalenecaceae" Xie et al. 2022
• * ?"Candidatus Nanosalenecus" Xie et al. 2022
• Family "Nucleotidisoteraceae" Xie et al. 2022
• * ?"Candidatus Nucleotidisoter" Xie et al. 2022
• Family "Nucleotidivindicaceae" Xie et al. 2022
• * ?"Nucleotidivindex" Xie et al. 2022

  Class "Nanohalobiia"

Order "Nanohalobiales"

• Family "Nanoanaerosalinaceae" Zhao et al. 2022
• * "Candidatus Asbonarchaeum" Baker et al. 2024
• * "Candidatus Nanoanaerosalina" Zhao et al. 2022
• Family "Nanohalalkaliarchaeaceae" La Cono et al. 2020
• * "Candidatus Nanohalalkaliarchaeum" Ghai et al. 2011
• Family "Nanohalobiaceae" La Cono et al. 2020
• * ?"Candidatus Haloredivivus" Ghai et al. 2011
• * "Candidatus Nanohalobium" La Cono et al. 2020
• * "Candidatus Nanohalococcus" Reva et al. 2023
• * "Candidatus Nanosalina" Narasingarao et al. 2012
• * "Candidatus Nanosalinicola" corrig. Narasingarao et al. 2012
• * "Candidatus Nanohalovita" Reva et al. 2023

  Phylum Nanobdellota">Nanoarchaeota">Nanobdellota

Class Nanobdellia

Order Nanobdellales

• Family "Nanoarchaeaceae" Huber et al. 2011
• * "Nanoarchaeum" Huber et al. 2002
• Family Nanobdellaceae Kato et al. 2022
• * Nanobdella Kato et al. 2022
• * "Candidatus Nanoclepta" St. John et al. 2019

  Order "Tiddalikarchaeales"

• Family "Tiddalikarchaeaceae" Vázquez-Campos et al. 2021
• * "Candidatus Tiddalikarchaeum" Vázquez-Campos et al. 2021

  Order "Jingweiarchaeales"

• Family "Jingweiarchaeaceae" Rao et al. 2023
• * "Candidatus Jingweiarchaeum" Rao et al. 2023

  Order JAPDLS01

• Family "Haiyanarchaeaceae" Rao et al. 2023
• * "Candidatus Haiyanarchaeum" Rao et al. 2023

  Order "Parvarchaeales"

• Family "Parvarchaeaceae" Rinke et al. 2020
• * "Candidatus Acidifodinimicrobium" Luo et al. 2020
• * "Candidatus Parvarchaeum" Baker et al. 2010
• * "Candidatus Rehaiarchaeum" Rao et al. 2023

  Phylum Promethearchaeota

Promethearchaeota incertae sedis

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

  Class "Asgardarchaeia"

Order "Asgardarchaeales"

• Family "Asgardarchaeaceae" Eme et al. 2023 ex Tamarit et al. 2024
• * "Candidatus Asgardarchaeum" Eme et al. 2023 ex Tamarit et al. 2024

  Class "Atabeyarchaeia"

Order "Atabeyarchaeales"

• Family "Atabeyarchaeaceae" Valentin-Alvaradoet al. 2024
• * "Candidatus Atabeyarchaeum" Valentin-Alvarado et al. 2024

  Class "Sifarchaeia"

Order "Sifarchaeales"

• Family "Sifarchaeaceae" Sun et al. 2021
• * "Candidatus Sifarchaeum" corrig. Farag, Zhao & Biddle 2020

  Order "Borrarchaeales"

• Family "Borrarchaeaceae" Liu et al. 2021
• * "Candidatus Borrarchaeum" Liu et al. 2021

  Class "Wukongarchaeia"

Order "Wukongarchaeales"

• Family "Wukongarchaeaceae" Liu et al. 2021
• * "Candidatus Wukongarchaeum" Liu et al. 2021

  Class "Njordarchaeia"

Order "Njordarchaeales"

• Family "Panguiarchaeaceae" Qu et al. 2023
• * "Panguiarchaeum" Qu et al. 2023
• Family "Njordarchaeaceae" Xie et al. 2022
• * "Candidatus Njordarchaeum" Xie et al. 2022

  Class "Heimdallarchaeia"

Order "[Wenzhongarchaeales]"

Order "Hodarchaeales"

• Family "Hodarchaeaceae" Liu et al. 2021
• * "Candidatus Hodarchaeum" Liu et al. 2021
• Family "Margulisarchaeaceae" Imachi et al. 2025
• * ?"Candidatus Flexarchaeum" Imachi et al. 2025
• * ?"Candidatus Margulisarchaeum" Imachi et al. 2025

  Order "[Gerdarchaeales]"

Order "Heimdallarchaeales"

• Family "Kariarchaeaceae" Liu et al. 2021
• * "Candidatus Kariarchaeum" Liu et al. 2021
• Family "Heimdallarchaeaceae" Wu et al. 2022
• * "Candidatus Heimdallarchaeum" Wu et al. 2022

  Class "Odinarchaeia"

Order "Odinarchaeales"

• Family "Odinarchaeaceae" Tamarit et al. 2022
• * "Candidatus Odinarchaeum" Tamarit et al. 2022

  Order "[Yangjianarchaeales]"

Class "Jordarchaeia"

Order "Jordarchaeales"

• Family "Freyrarchaeaceae" Xie et al. 2022
• * "Candidatus Freyrarchaeum" Xie et al. 2022
• Family "Jordarchaeaceae" Sun et al. 2021
• * "Candidatus Jordarchaeum" Sun et al. 2021

  Class "Baldrarchaeia"

Order "Baldrarchaeales"

• Family "Baldrarchaeaceae" corrig. Liu et al. 2021
• * "Candidatus Baldrarchaeum" Liu et al. 2021

  Class "[Thorarchaeia]"

Order "Thorarchaeales"

• Family "Thorarchaeaceae"

  Class "Hermodarchaeia"

Order "Hermodarchaeales"

• Family "Hermodarchaeaceae" corrig. Liu et al. 2021
• * "Candidatus Hermodarchaeum" Liu et al. 2021

  Class Promethearchaeia">Lokiarchaeia">Promethearchaeia

Order "Helarchaeales">Helarchaeota">Helarchaeales"

Order Promethearchaeales">Promethearchaeaceae">Promethearchaeales

• Family Sigynarchaeaceae Xie et al. 2022
• * "Candidatus Sigynarchaeum" Xie et al. 2022
• Family Promethearchaeaceae Imachi et al. 2024
• * "Candidatus Harpocratesius" Wu et al. 2022
• * "Candidatus Lokiarchaeum" corrig. Spang et al. 2015
• * Promethearchaeum Imachi et al. 2024

  Phylum "[Korarchaeota]"

Class "Korarchaeia"

Order "Korarchaeales"

• Family "Korarchaeaceae" Rinke et al. 2020
• * "Candidatus Korarchaeum" Elkins et al. 2008
• * "Candidatus Methanodesulfokora" McKay et al. 2019

  Phylum [Thermoproteota]

Thermoproteota Incertae sedis

"[Brockiarchaeota]"

Class "[Bathyarchaeia]"

Order "Bifangarchaeales"

• Family "Bifangicolaceae" Hou et al. 2023
• * ?"Candidatus Bifangicola" Hou et al. 2023
• Family "Bifangarchaeaceae" Hou et al. 2023
• * "Candidatus Bifangarchaeum" corrig. Hou et al. 2023
• Family "Bifangistellaceae" Hou et al. 2023
• * "Candidatus Bifangistella" Hou et al. 2023

  Order "Xuanwuarculales"

• Family "Mazuisomaceae" Hou et al. 2023
• * ?"Candidatus Mazuisoma" Hou et al. 2023
• Family "Mazuicellaceae" Hou et al. 2023
• * ?"Candidatus Mazuibellus" Hou et al. 2023
• * ?"Candidatus Mazuicella" Hou et al. 2023
• Family "Mazuousiaecae" Hou et al. 2023
• * ?"Candidatus Mazuarcula" Hou et al. 2023
• * ?"Candidatus Mazuousia" Hou et al. 2023
• Family "Xuanwuarculaceae" Hou et al. 2023
• * "Candidatus Xuanwuarcula" Hou et al. 2023

  Order "Hecatellales"

• Family "Hecatellaceae" Rinke et al. 2020
• * "Candidatus Hecatella" Adam et al. 2022
• * "Candidatus Jinwuarcula" Hou et al. 2023
• * "Candidatus Jinwuicola" Hou et al. 2023
• * ?"Candidatus Jinwuimonas" Hou et al. 2023
• * "Candidatus Jinwuimorpha" Hou et al. 2023
• * ?"Candidatus Jinwuiprofundus" Hou et al. 2023
• * ?"Candidatus Jinwuousia" Hou et al. 2023

  Order "Houtuarculales"

• Family "Houtuithermaceae" Hou et al. 2023
• * ?"Candidatus Houtuithermus" Hou et al. 2023
• Family "Marihoutuimonadaceae" Hou et al. 2023
• * ?"Candidatus Houtuibellus" Hou et al. 2023
• * ?"Candidatus Marihoutuimonas" Hou et al. 2023
• Family "Crenohoutuithermaceae" Hou et al. 2023
• * "Candidatus Crenohoutuithermus" Hou et al. 2023
• Family "Fontihoutuithermaceae" Hou et al. 2023
• * ?"Candidatus Fluxihoutuithermus" Hou et al. 2023
• * "Candidatus Fontihoutuithermus" Hou et al. 2023
• Family "Aphrohoutuibellaceae" Hou et al. 2023
• * "Candidatus Aphrohoutuibellus" Hou et al. 2023
• * "Candidatus Hydrohoutuibellus" Hou et al. 2023
• Family "Houtuousiaceae" Hou et al. 2023
• * "Candidatus Houtuousia" Hou et al. 2023
• Family "Houtuarculaceae" Hou et al. 2023
• * ?"Candidatus Limnohoutuiplasma" Hou et al. 2023
• * "Candidatus Houtuarcula" Hou et al. 2023

  Order "Wuzhiqiibiales"

• Family "Wuzhiqiithermaceae" Hou et al. 2023
• * ?"Candidatus Wuzhiqiithermus" Hou et al. 2023
• Family "Wuzhiqiitorraceae" Hou et al. 2023
• * ?"Candidatus Wuzhiqiitorris" Hou et al. 2023
• Family "Wuzhiqiimorphaceae" Hou et al. 2023
• * "Candidatus Wuzhiqiimorpha" Hou et al. 2023
• Family "Wuzhiqiimonadaceae" Hou et al. 2023
• * "Candidatus Wuzhiqiimonas" Hou et al. 2023
• Family "Wuzhiqiibiaceae" Hou et al. 2023
• * "Candidatus Wuzhiqiibium" Hou et al. 2023

  Order "Zhuquarculales"

• Family "Zhuquarculaceae" Hou et al. 2023
• * "Candidatus Zhuquarcula" Hou et al. 2023
• Family "Zhuquomorphaceae" Hou et al. 2023
• * "Candidatus Zhuquomorpha" Hou et al. 2023

  Order "Bathyarchaeales"

• Family "Actozhurongousiaceae" Hou et al. 2023
• * ?"Candidatus Actozhurongousia" Hou et al. 2023
• Family "Yuguousiaceae" Hou et al. 2023
• * ?"Candidatus Yuguousia" Hou et al. 2023
• Family "Pontizhurongicolaceae" Hou et al. 2023
• * "Candidatus Pontizhurongicola" Hou et al. 2023
• Family "Hanbarchaeaceae" Hou et al. 2023
• * "Candidatus Fufeiimorpha" Hou et al. 2023
• * "Candidatus Hanbarchaeum" Hou et al. 2023
• * "Candidatus Zhurongicella]" Hou et al. 2023
• Family "Marizhurongicellaceae" Hou et al. 2023
• * ?"Candidatus Aoguangisoma" Hou et al. 2023
• * "Candidatus Marizhurongibium" Hou et al. 2023
• * "Candidatus Marizhurongicella" Hou et al. 2023
• * ?"Candidatus Yanziimonas" Hou et al. 2023
• * ?"Candidatus Zhurongibium" Hou et al. 2023
• Family "Hanbopyraceae" Hou et al. 2023
• * "Candidatus Hanbopyrus" Hou et al. 2023
• Family "Jingweiiplasmataceae" Hou et al. 2023
• * "Candidatus Jingweiiplasma" Hou et al. 2023
• Family "Bathyarchaeaceae" Khomyakova et al. 2023
• * "Candidatus Baizobellus" Hou et al. 2023
• * ?"Candidatus Baizosediminiarchaeum" Yu et al. 2023
• * "Candidatus Baizosoma" Hou et al. 2023
• * ?"Candidatus Baizostella" Hou et al. 2023
• * "Candidatus Bathyarchaeum" Khomyakova et al. 2023
• * "Candidatus Halozhurongicella" Hou et al. 2023
• Family "Bathycorpusculaceae" Loh & Brune 2023
• * ?"Candidatus Aoshunithermus" Hou et al. 2023
• * ?"Candidatus Baizomonas" Hou et al. 2023
• * "Candidatus Baizomorpha" Hou et al. 2023
• * "Candidatus Bathycorpusculum" Loh & Brune 2023
• * "Candidatus Buyanhuyuicella" Hou et al. 2023
• * "Candidatus Buyanhuyuitorris" Hou et al. 2023
• * "Candidatus Hanbocola" Hou et al. 2023
• * "Candidatus Hanbothermus" Hou et al. 2023
• * "Candidatus Yanziithermus" Hou et al. 2023
• * "Candidatus Yuguotorris" Hou et al. 2023

  Class Nitrososphaeria_A">Nitrososphaerota">Nitrososphaeria_A

Order "Caldarchaeales"

• Family "Calditenuaceae" Balbay et al. 2023
• * "Candidatus Calditenuis" Beam et al. 2016
• Family "Caldarchaeaceae" Rinke et al. 2020
• * "Candidatus Caldarchaeum" corrig. Nunoura et al. 2011
• * "Candidatus Pelearchaeum" Balbay et al. 2023
• Family "Wolframiiraptoraceae" Buessecker et al. 2022
• * "Candidatus Benthortus" Buessecker et al. 2022
• * "Candidatus Geocrenenecus" Buessecker et al. 2022
• * "Candidatus Terraquivivens" Buessecker et al. 2022
• * "Candidatus Wolframiiraptor" Buessecker et al. 2022

  Class Nitrososphaeria">Nitrososphaerota">Nitrososphaeria

Nitrososphaeria incertae sedis

• ?"Candidatus Cenoporarchaeum" corrig. Zhang et al. 2019
• ?"Candidatus Gigantothauma" corrig. Muller et al. 2010
• ?"Candidatus Nitrosodeserticola" Hwang et al. 2021

  Order "Geothermarchaeales"

• Family "Geothermarchaeaceae" Adam et al. 2022
• * "Candidatus Geothermarchaeum" Adam et al. 2022
• * "Candidatus Scotarchaeum" Adam et al. 2022

  Order PSMU01

• Family PSMU01
• * "Candidatus Australarchaeum" Herbold et al. 2024

  Order "Conexivisphaerales"

• Family "Conexivisphaeraceae" Kato et al. 2021
• * Conexivisphaera Kato et al. 2021

  Order [Nitrososphaerales]

• Family "Methylarchaceae" Hua et al. 2019
• * ?"Candidatus Methylarchaeum" Hua et al. 2019
• * ?"Candidatus Methanotowutia" Ou et al. 2022
• Family "Gagatemarchaeaceae" Sheridan et al. 2023
• * "Candidatus Gagatemarchaeum" Sheridan et al. 2023
• * ?"Candidatus Subgagatemarchaeum" Sheridan et al. 2023
• Family "Nitrosocaldaceae" Qin et al. 2016
• * "Candidatus Nitrosocaldus" de la Torre et al. 2008
• * "Candidatus Nitrosothermus" Luo et al. 2021
• Family "Nitrosomiraceae" Zheng et al. 2024
• * "Candidatus Nitrosomirus" Zheng et al. 2024
• Family Nitrososphaeraceae Stieglmeier et al. 2014
• * "Candidatus Nitrosocosmicus" corrig. Lehtovirta-Morley et al. 2016
• * "Candidatus Nitrosopolaris" Pessi, Rutanen & Hultman 2022
• * Nitrososphaera Stieglmeier et al. 2014
• Family Nitrosopumilaceae Qin et al. 2017
• * "Cenarchaeum" DeLong & Preston 1996
• * Nitrosarchaeum corrig. Jung et al. 2018
• * "Candidatus Nitrosoabyssus" Garritano et al. 2024
• * ?"Candidatus Nitrosokoinonia" Glasl et al. 2023
• * "Candidatus Nitrosomaritimum" Zhao et al. 2024
• * "Candidatus Nitrosopelagicus" Santoro et al. 2015
• * Nitrosopumilus Qin et al. 2017
• * ?"Candidatus Nitrosospongia" Moeller et al. 2019
• * "Candidatus Nitrosotalea" Lehtovirta 2011
• * "Candidatus Nitrosotenuis" Lebedeva et al. 2013

  Class "Methanomethylicia"

• Order "Methanohydrogenicales"
• * Family "Methanohydrogenicaceae" Berghuis et al. 2019
• ** ?"Candidatus Methanohydrogenicus" Berghuis et al. 2019
• Order "Methanomethylarchaeales"
• * Family "Methanomethylarchaeceae" corrig. Hua et al. 2019
• ** ?"Candidatus Methanomethylarchaeum" corrig. Hua et al. 2019
• Order "Methanomethylovorales"
• * Family "Methanomethylovoraceae" Hua et al. 2019
• ** ?"Candidatus Methanomethylovorus" Hua et al. 2019

  Order "Nezhaarchaeales"

• Family "Methanohydrogenotrophicaceae" Hua et al. 2019
• * ?"Candidatus Methanogearchaeum" corrig. Hua et al. 2019
• * ?"Candidatus Methanohydrogenotrophicum" Hua et al. 2019

  Order "Culexarchaeles"

• Family "Culexarchaeaceae" Kohtz et al. 2022
• * "Candidatus Culexarchaeum" Kohtz et al. 2022
• Family "Culexmicrobiaceae" Kohtz et al. 2022
• * "Candidatus Culexmicrobium" Kohtz et al. 2022

  Order "Methanosuratincolales"

• Family "Candidatus Methanosuratincolaceae" Wu et al. 2025
• * ?"Candidatus Methanoluiimicrobium" Wu et al. 2024
• * "Candidatus Methanomethylicus" Vanwonterghem et al. 2016
• * ?"Candidatus Methanostamsia" Wu et al. 2024
• * "Candidatus Methanosuratinicola" corrig. Vanwonterghem et al. 2016

  Class [Thermoprotei]a

Order "Gearchaeales"

• Family "Gearchaeaceae" corrig.
• * ?Geoarchaeum Hunt et al. 2016

  Order Thermofilales

• Family Thermofilaceae Burggraf, Huber & Stetter 1997
• * Infirmifilum Zayulina et al. 2021
• * Thermofilum Zillig & Gierl 1983

  Order [Thermoproteales]

• Family Thermocladiaceae Chuvochina et al. 2024
• * Caldivirga Itoh et al. 1999
• * Thermocladium Itoh, Suzuki & Nakase 1998
• * Vulcanisaeta Itoh, Suzuki & Nakase 2002
• Family Thermoproteaceae Zillig & Stetter 1982
• * Pyrobaculum Huber, Kristjansson & Stetter 1988
• * Thermoproteus Zillig & Stetter 1982

  Class "Sulfolobia"

Order "Tardisphaerales"

• Family "Marsarchaeaceae"
• Family "Tardisphaerace" Prokofeva et al. 2025
• * ?"Tardisphaera" Prokofeva et al. 2025

  Order [Sulfolobales]

• Family Desulfurococcaceae Zillig & Stetter 1983
• * Desulfurococcus Zillig & Stetter 1983
• * Staphylothermus Stetter & Fiala 1986
• * ?Sulfophobococcus Hensel et al. 1997
• * Thermogladius Osburn & Amend 2011 ex Kochetkova et al. 2016
• * Thermosphaera Huber et al. 1998
• * ?"Candidatus Zestomicrobium" Dzhuraeva, Bobodzhanova & Birkeland 2024
• Family Fervidicoccaceae Perevalova et al. 2010
• * Fervidicoccus Perevalova et al. 2010
• Family Pyrodictiaceae Burggraf, Huber & Stetter 1997
• * ?Geogemma Kashefi, Holmes & Lovley 2006
• * Hyperthermus Zillig, Holz & Wunderl 1991
• * Pyrodictium Stetter, König & Stackebrandt 1984
• * "Pyrofollis" Miyazaki et al. 2023
• * Pyrolobus Blochl et al. 1999
• Family Acidilobaceae Prokofeva et al. 2009
• * Aeropyrum Sako et al. 1996
• * Acidilobus Prokofeva et al. 2000
• * Caldisphaera Itoh et al. 2003
• * "Candidatus Calypsonella" St John and Reysenbach 2024
• * ?Stetteria Jochimsen, Peinemann-Simon & Thomm 1998
• * Thermodiscus Stetter 2003
• * "Candidatus Tiamatella" St John and Reysenbach 2024
• Family Ignisphaeraceae RChuvochina et al. 2024
• * Ignisphaera Niederberger et al. 2006
• Family "Zestosphaeraceae" Pallen, Rodriguez-R & Alikhan 2022
• * Zestosphaera St. John et al. 2021
• Family Ignicoccaceae Chuvochina et al. 2024
• * Ignicoccus Huber, Burggraf & Stetter 2000
• Family Sulfolobaceae Stetter 1989
• * Acidianus Segerer et al. 1986
• * "Candidatus Aramenus" Servín-Garcidueñas & Martínez-Romero 2014
• * ?"Caldariella" de Rosa, Gambacorta & Bu'lock 1975
• * Metallosphaera Huber et al. 1989
• * Saccharolobus Sakai & Kurosawa 2018
• * Stygiolobus Segerer et al. 1991
• * Sulfodiicoccus Sakai & Kurosawa 2017
• * Sulfolobus Brock et al. 1972
• * Sulfuracidifex Itoh et al. 2020
• * Sulfurisphaera Kurosawa et al. 1998
• * ?Sulfurococcus Golovacheva, Vale’kho & Troitskii 1995

  Phylum "[Hadarchaeota]"

Class "[Persephonarchaeia]"

Class "Hadarchaeia"

Order "Hadarchaeales"

• Family "Cerberiarchaeaceae" Benito Merino et al. 2024
• * ?"Candidatus Cerberiarchaeum" Benito Merino et al. 2024
• * ?"Candidatus Melinoarchaeum" Yu et al. 2024
• Family "Hadarchaeaceae" Chuvochina et al. 2019 ex Chuvochina et al. 2023
• * "Candidatus Hadarchaeum" Chuvochina et al. 2019
• * ?"Candidatus Hadesarchaeum" Hua et al. 2019
• * ?"Candidatus Methanourarchaeum" Hua et al. 2019

  Phylum Methanobacteriota_B

Class "[Theionarchaeia]"

Class [Thermococci]

Order "Methanofastidiosales"

• Family "Methanofastidiosaceae" Rinke et al. 2020
• * "Candidatus Methanofastidiosum" Nobu et al. 2016

  Order [Thermococcales]

• Family Thermococcaceae Zillig et al. 1988
• * Palaeococcus Takai et al. 2000
• * Pyrococcus Fiala & Stetter 1986
• * Thermococcus Zillig 1983

  Phylum "[Hydrothermarchaeota]"

Class "Hydrothermarchaeia"

Order "Hydrothermarchaeales"

• Family BMS3B
• * "Candidatus Pyrohabitans" Adam et al. 2022
• Family "Hydrothermarchaeaceae" Chuvochina et al. 2019
• * "Candidatus Hydrothermarchaeum" Chuvochina et al. 2019

  Phylum [Methanobacteriota]

Class "[Methanococci]a"

Order [Methanococcales]

• Family Methanocaldococcaceae Whitman 2002
• * Methanocaldococcus Whitman 2002
• Family Methanococcaceae Balch & Wolfe 1981
• * Methanococcus Kluyver & van Niel 1936
• * Methanofervidicoccus Sakai et al. 2019
• * Methanothermococcus Whitman 2002
• * Methanotorris Whitman 2002

  Class [Methanopyri]a

Order [Methanopyrales]

• Family Methanopyraceae Huber & Stetter 2002
• * Methanopyrus Kurr et al. 1992

  Class Methanobacteriia">Methanobacteria">Methanobacteriia

Order [Methanobacteriales]

• Family Methanothermaceae Stetter et al. 1982
• * Methanothermus Stetter et al. 1982
• Family Methanothermobacteraceae Chuvochina et al. 2024
• * Methanothermobacter Wasserfallen et al. 2000
• Family Methanobacteriaceae Barker 1956
• * "Methanacia" Protasov & Brune 2023
• * "Methanarmilla" Protasov & Brune 2023
• * Methanobacterium Kluyver & van Niel 1936
• * "Methanobaculum" Protasov & Brune 2023
• * "Methanobinarius" Protasov & Brune 2023
• * Methanobrevibacter Balch & Wolfe 1981
• * "Methanocatella" Protasov & Brune 2023
• * "Methanoflexus" Protasov & Brune 2023
• * "Methanorudis" Protasov & Brune 2023
• * Methanosphaera Miller & Wolin 1985
• * "Methanovirga" Protasov & Brune 2023

  Phylum [Thermoplasmatota]

Class "Izemarchaea"

Order "[Thermoprofundales]"

• Class "Poseidoniia"

Order MGIII

Order "Poseidoniales"

• Family "Poseidoniaceae" Rinke et al. 2019
• * "Candidatus Poseidonia" Rinke et al. 2019
• Family "Thalassarchaeaceae" Rinke et al. 2019
• * "Candidatus Thalassarchaeum" corrig. Martin-Cuadrado et al. 2015

  Class "Penumbrarchaeia"

Order "Penumbrarchaeales"

• Family "Penumbrarchaeaceae" Maeke et al. 2025
• * "Candidatus Penumbrarchaeum" Maeke et al. 2025

  Class [Thermoplasmata]

Order "Angelarchaeales"

Order "Lunaplasmatales"

• Family "Lunaplasmataceae" corrig. Zinke et al. 2021
• * ?"Candidatus Lunaplasma" Zinke et al. 2021

  Order "Proteinoplasmatales"

• Order "[Yaplasmatales]"

• Order "Gimiplasmatales"

• Family "Gimiplasmataceae" Hu et al. 2020
• * "Candidatus Gimiplasma" Hu et al. 2020

  Order "Sysuiplasmatales"

• Family "Sysuiplasmataceae" Yuan et al. 2021
• * "Candidatus Sysuiplasma" Yuan et al. 2021

  Order [Methanomassiliicoccales]

• Family "Methanomixtatrophicaceae" Hua et al. 2019
• * ?"Candidatus Methanomixtatrophicum" Hua et al. 2019
• Family Methanomassiliicoccaceae Iino et al. 2013
• * Methanomassiliicoccus Dridi et al. 2012
• Family Methanomethylophilaceae Gaci et al. 2014 ex Borrel et al. 2024
• * "Methanarcanum" Chibani et al. 2023
• * "Methanogranum" Iino et al. 2023
• * Methanomethylophilus Borrel et al. 2024
• * "Candidatus Methanomicula" Protasov & Brune 2023
• * "Methanoplasma" Lang & Brune 2023
• * "Methanoprimaticola" Chibani et al. 2023
• * ?"Candidatus Methanospyradousia" Gilroy et al. 2021

  Order "Halarchaeoplasmatales"

• Family "Halarchaeoplasmataceae" Zhou et al. 2023
• * "Candidatus Haladaptiplasma" corrig. Zhou et al. 2022
• * "Candidatus Halarchaeoplasma" Zhou et al. 2023
• * "Candidatus Natronoplasma" Zhou et al. 2022
• * "Candidatus Saliniplasma" Zhou et al. 2022

  Order "Lutacidiplasmatales"

• Family "Lutacidiplasmataceae" Sheridan et al. 2022
• * "Candidatus Lutacidiplasma" Sheridan et al. 2022

  Order "Aciduliprofundales"

• Family "Aciduliprofundaceae" Rinke et al. 2020
• * "Aciduliprofundum" Reysenbach et al. 2006

  Order [Thermoplasmatales]

• Family Thermoplasmataceae Reysenbach 2002
• * Acidiplasma Golyshina et al. 2009
• * ?"Candidatus Carboxiplasma" Bulaev et al. 2023
• * Cuniculiplasma corrig. Golyshina et al. 2016
• * Ferroplasma Golyshina et al. 2000
• * ?Oxyplasma Golyshina et al. 2024
• * Picrophilus Schleper et al. 1996
• * ?"Candidatus Scheffleriplasma" Krause et al. 2022
• * Thermogymnomonas Itoh, Yoshikawa & Takashina 2007
• * Thermoplasma Darland et al. 1970

  Phylum [Halobacteriota]

Halobacteriota incertae sedis

• ?"Candidatus Methanoinsularis" Ou et al. 2022
• ?"Candidatus Methanoporticola" Ou et al. 2022
• Order "Methanoflorentales"
• * Family "Methanoflorentaceae" Mondav et al. 2014
• ** ?"Candidatus Methanoflorens" Mondav et al. 2014

  Class "Methanonatronarchaeia"

Order "Methanonatronarchaeales"

• Family Methanonatronarchaeaceae Sorokin et al. 2018
• * "Candidatus Methanohalarchaeum" Sorokin et al. 2018
• * Methanonatronarchaeum Sorokin et al. 2018

  Class "Methanoliparia"

Order "Methanoliparales"

• Family "Methanoliparaceae" Borrel et al. 2019
• * "Candidatus Methanoliparum" Borrel et al. 2019
• * "Candidatus Methanolliviera" Borrel et al. 2019

  Class "[Archaeoglobi]a"

Order "Mnemosynellales"

• Family "Mnemosynellaceae" Adam et al. 2022
• * "Candidatus Mnemosynella" Adam et al. 2022

  Order [Archaeoglobales]

• Family "Allopolytropaceae" corrig. Boyd et al. 2019
• * ?"Candidatus Allopolytropus" corrig. Boyd et al. 2019
• Family Archaeoglobaceae Huber & Stetter 2002
• * Archaeoglobus Stetter 1988
• * Ferroglobus Hafenbradl et al. 1997
• * Geoglobus Kashefi et al. 2002
• * ?"Candidatus Methanoglobus" Buessecker et al. 2023
• * ?"Candidatus Methanomixotrophus" corrig. Liu et al. 2021
• * ?"Candidatus Methanoproducendum" Hua et al. 2019

  Class "Syntropharchaeia"

Order "Aerarchaeales"

• Family YL-1
• * "Candidatus Methanodefluvium" Leu et al. 2025
• Family "Aerarchaeaceae" Leu et al. 2025
• * "Candidatus Aerarchaeum" Leu et al. 2025
• * "Candidatus Aerovita" Leu et al. 2025

  Order "Syntropharchaeales"

• Family "Syntropharchaeaceae"
• * "Candidatus Syntropharchaeum" corrig. Laso-Perez et al. 2016

  Order "Alkanophagales"

• Family "Methanophagaceae" Chadwick et al. 2022
• * ?"Candidatus Methanoalium" Chadwick et al. 2022
• * ?"Candidatus Methanophaga" Chadwick et al. 2022
• Family ?"Veteromethanophagaceae" Vulcano et al. 2022
• Family "Alkanophagaceae"
• * "Candidatus Alkanophaga" Zehnle et al. 2023
• Family "Methanospiraraceae" Laso-Pérez et al. 2022
• * "Candidatus Methanospirare" Laso-Pérez et al. 2022
• * "Candidatus Methanoxibalbensis" Laso-Pérez et al. 2022

  Class Methanocellia

Order Methanocellales

• Family Methanocellaceae Sakai et al. 2008
• * Methanocella Sakai et al. 2008
• * Methanooceanicella Zhang et al. 2024

  Class Methanosarcinia

Order Methanotrichales

• Family Methanotrichaceae Akinyemi et al. 2021
• * "Candidatus Methanocrinis" Khomyakova et al. 2023
• * Methanothrix Huser, Wuhrmann & Zehnder 1983

  Order Methanosarcinales_A

• Methermicoccus Cheng et al. 2007

  Order [Methanosarcinales]

• Family "Methanogastraceae" corrig. Chadwick et al. 2022
• * "Candidatus Methanogaster" Chadwick et al. 2022
• Family "Methanocomedentaceae" corrig. Chadwick et al. 2022
• * "Candidatus Methanocomedens" Chadwick et al. 2022
• * "Candidatus Methanomarinus" Chadwick et al. 2022
• Family "Ethanoperedentaceae" Pallen, Rodriguez-R & Alikhan 2022
• * "Candidatus Ethaniperedens" corrig. Hahn et al. 2020
• Family "Methanoperedentaceae" corrig. Haroon et al. 2013
• * "Candidatus Methanoperedens" Haroon et al. 2013
• Family Methanosarcinaceae Balch & Wolfe 1981
• * ?Halomethanococcus Yu & Kawamura 1988
• * Methanimicrococcus corrig. Sprenger et al. 2000
• * Methanococcoides Sowers & Ferry 1985
• * "Methanofrustulum" Protasov & Brune 2023
• * Methanohalobium Zhilina & Zavarzin 1988
• * Methanohalophilus Paterek & Smith 1988
• * Methanolapillus Protasov & Brune 2025
• * Methanolobus König & Stetter 1983
• * Methanomethylovorans Lomans et al. 2004
• * Methanosalsum Boone & Baker 2002
• * Methanosarcina Kluyver & van Niel 1936
• * ?"Candidatus Methanovorans" Chadwick et al. 2022

  Class "[Methanomicrobia]"

Order [Methanomicrobiales]

• Family Methanocorpusculaceae Zellner et al. 1989
• * Methanocalculus Ollivier et al. 1998
• * Methanocorpusculum Zellner et al. 1988
• Family Methanofollaceae Chuvochina et al. 2024
• * Methanofollis Zellner et al. 1999
• Family Methanospirillaceae Boone et al. 2002
• * "Methanofilum" Protasov & Brune 2023
• * Methanolinea Imachi et al. 2008
• * Methanoregula Brauer et al. 2011
• * Methanosphaerula Cadillo-Quiroz et al. 2009
• * Methanospirillum Ferry, Smith & Wolfe 1974
• Family Methanoculleaceae Chuvochina et al. 2024
• * Methanoculleus Maestrojun et al. 1990
• Family Methanomicrobiaceae Balch & Wolfe 1981
• * ?Methanochimaera Zhou et al. 2024
• * Methanogenium Romesser et al. 1981
• * Methanolacinia Zellner et al. 1990
• * Methanomicrobium Balch & Wolfe 1981
• * Methanoplanus Wildgruber et al. 1984
• * Methanovulcanius Chien et al. 2023

  Class "Hikarchaeia"

Order "Hikarchaeales"

• Family "Hikarchaeaceae" Martijn et al. 2020
• * ?"Candidatus Hikarchaeum" Martijn et al. 2020

  Class "Ordosarchaeia"

Order "Ordosarchaeales"

• Family "Ordosarchaeaceae" Zhao et al. 2024
• * ?"Candidatus Ordosarchaeum" Zhao et al. 2024

  Class [Halobacteria]

Order Halorutilales

• Family Halorutilaceae Durán-Viseras et al. 2023
• * "Candidatus Afararchaeum" Baker et al. 2024
• * Halorutilus Durán-Viseras et al. 2023

  Order [Halobacteriales]

• ?"Haloalcalophilium" Lizama et al. 2000a
• Family "Chewarchaeaceae" Baker et al. 2024
• * "Candidatus Chewarchaeum" Baker et al. 2024
• Family "Halalkalicoccaceae" Mao et al. 2025
• * Halalkalicoccus Xue et al. 2005
• * ?Natronorarus Mao et al. 2025
• Family "Salinarchaeaceae"
• * Salinarchaeum Cui et al. 2014
• Family "Halostellaceae" Pallen, Rodriguez-R & Alikhan 2022
• * Halostella Song et al. 2016
• Family Natronoarchaeaceae Sorokin et al. 2023
• * Natranaeroarchaeum Sorokin et al. 2023
• * Natronoarchaeum Shimane et al. 2010
• Family Natrialbaceae Gupta et al. 2015
• * Haloarchaeobius Makhdoumi-Kakhki et al. 2012
• * Halobiforma Hezayen et al. 2002
• * Halomontanus Mao et al. 2024
• * Halopiger Gutierrez et al. 2007
• * Halorubellus Cui et al. 2014
• * Halosolutus Sun et al. 2022
• * Halostagnicola Castillo et al. 2006
• * Haloterrigena Ventosa et al. 1999
• * ?Halovalidus Dong et al. 2025
• * Halovivax Castillo et al. 2006
• * Natrarchaeobaculum Sorokin et al. 2020
• * Natrarchaeobius corrig. Sorokin et al. 2020
• * Natrialba Kamekura & Dyall-Smith 1996
• * Natribaculum Liu et al. 2015
• * Natronobacterium Tindall et al. 1984
• * Natronobiforma Sorokin et al. 2019
• * Natronococcus Tindall et al. 1984
• * Natronolimnobius Itoh et al. 2005
• * Natronolimnohabitans Sorokin et al. 2020
• * Natrinema McGenity et al. 1998
• * Natronobeatus Li et al. 2023
• * Natrononativus Li et al. 2023
• * Natronorubrum Xu et al. 1999
• * Natronosalvus Tan et al. 2023
• * Salinadaptatus Xue et al. 2020
• * Salinilacihabitans Li et al. 2023
• * Saliphagus Yin et al. 2017
• Family Haladaptataceae Rinke et al. 2020
• * Haladaptatus Savage et al. 2007
• * Halomicrococcus Chen et al. 2020
• * Halorussus Cui et al. 2014
• Family Halobacteriaceae
• * Halanaeroarchaeum Sorokin et al. 2016
• * Halarchaeum Minegishi et al. 2010
• * Halobacterium Elazari-Volcani 1957
• * Halocalculus Minegishi et al. 2015
• * Halodesulfurarchaeum Sorokin et al. 2017
• * Halospeciosus Li et al. 2024
• * Salarchaeum Shimane et al. 2011
• Family Halococcaceae Gupta et al. 2016
• * Halococcus Schoop 1935
• Family Haloarculaceae
• * Halapricum Song et al. 2014
• * Haloarcula Torreblanca et al. 1986
• * Halocatena Verma et al. 2020
• * Halococcoides Sorokin et al. 2019
• * Haloglomus Duran-Viseras, Sanchez-Porro & Ventosa 2020
• * Halomarina Inoue et al. 2011
• * Halomicroarcula Echigo et al. 2013
• * Halomicrobium Oren et al. 2002
• * Halorientalis Cui et al. 2011
• * Halorarius Sun et al. 2023
• * Halorhabdus Waino et al. 2000
• * Halosegnis Duran-Viseras et al. 2022
• * Halosimplex Vreeland et al. 2003
• * Halovenus Makhdoumi-Kakhki et al. 2012
• * Natronomonas Kamekura et al. 1997
• * Salinibaculum Han & Cui 2020
• * Salinirubellus Hou et al. 2018
• * Salinirussus Cui et al. 2017
• Family Haloferacaceae Gupta et al. 2015
• * Halalkaliarchaeum Sorokin et al. 2019
• * Halalkalirubrum Zuo et al. 2021
• * ?"Candidatus Halectosymbiota" corrig. Filker et al. 2014
• * Halegenticoccus Liu et al. 2022
• * Halobaculum Oren et al. 1995
• * Halobellus Cui et al. 2011
• * Halobium Mori et al. 2016
• * Haloferax Torreblanca et al. 1986
• * Halogeometricum Montalvo-Rodriguez et al. 1998
• * Halogranum Cui et al. 2010
• * Halohasta Mou et al. 2013
• * Halolamina Cui et al. 2011
• * Halonotius Burns et al. 2010
• * Haloparvum Chen et al. 2016
• * Halopelagius Cui et al. 2010
• * Halopenitus Amoozegar et al. 2012
• * Haloplanus Elevi Bardavid et al. 2007
• * Haloprofundus Zhang et al. 2017
• * Haloquadratum Burns et al. 2007
• * Halorubrum McGenity & Grant 1996
• * Natronocalculus Sorokin et al. 2023
• * ?Salinirarus Zhang et al. 2025
• * Salinirubrum corrig. Cui & Qiu 2014
• * Salinigranum Cui & Zhang 2014