After NCBI (National Center for Biotechnology Information)

<==o Thermoproteales Zillig and Stetter 1982 emend. Burggraf et al. 1997
   |--o Thermofilaceae 
   |  |-- Thermofilaceae archaeon SRI-325 
   |  |-- Thermofilaceae archaeon SRI-370 
   |  `--o Thermofilum 
   |     |-- Thermofilum librum Stetter 1986
   |     `-- Thermofilum pendens Zillig and Gierl 1983
   `--o Thermoproteaceae 
      |--o Caldivirga 
      |  `-- Caldivirga maquilingensis Itoh et al. 1999
      |--o Pyrobaculum 
      |  |-- Pyrobaculum aerophilum Volkl et al. 1996
      |  |-- Pyrobaculum arsenaticum Huber et al. 2001
      |  |-- Pyrobaculum calidifontis Amo et al. 2002
      |  |-- Pyrobaculum islandicum Huber et al. 1988
      |  |-- Pyrobaculum neutrophilum 
      |  |-- Pyrobaculum oguniense Sako et al. 2001
      |  |-- Pyrobaculum organotrophum Huber et al. 1988
      |  |-- Pyrobaculum sp. 14b 
      |  |-- Pyrobaculum sp. D11 
      |  |-- Pyrobaculum sp. M0H 
      |  |-- Pyrobaculum sp. M1T  
      |  `-- Pyrobaculum sp. WIJ3 
      |--o Thermocladium 
      |  `-- Thermocladium modestius Itoh et al. 1998
      |--o Thermoproteus 
      |  |-- Thermoproteus neutrophilus Zillig 1989
      |  |-- Thermoproteus tenax Zillig and Stetter 1982
      |  |-- Thermoproteus sp. IC-031 
      |  |-- Thermoproteus sp. IC-033 
      |  |-- Thermoproteus sp. IC-061 
      |  |-- Thermoproteus sp. IC-062 
      |  `-- Thermoproteus sp. IC-070 
      `--o Vulcanisaeta 
         |-- Vulcanisaeta distributa Itoh et al. 2002
         `-- Vulcanisaeta souniana Itoh et al. 2002

Reference(s):

• Anonymus - National Center for Biotechnology Information, Taxonomy homepage: Archaea - Thermoproteales
  - iNet: http://www.ncbi.nlm.nih.gov/Taxonomy/