What is the relationship between taxa with suffixes and taxa without suffixes?

Dear all,
I’m a bit confused about the relationship between taxa with suffixes and taxa without suffixes. I am very much looking forward to having my confusion cleared up, and would appreciate it!

For example, what’s the relationship between p__Desulfobacterota and p__Desulfobacterota_B/C/D/E/G/I?

Also, I noticed that p__Desulfobacterota_F was merged into p__Desulfobacterota in r207. What caused the frequent migration of certain taxa?

Last, this paper (DOI: 10.1099/ijsem.0.004213) argued that delta-proteobacteria should be reclassified into four phylums: Desulfobacterota, Myxococcota, SAR324, Bdellovibrionota, are p__Desulfobacterota_B/C/D/E/F/G/I belong to delta-proteobacteria or not?

Thank you all!


You can find details on alphabetic suffixes in the GTDB FAQ:

I’ll ask other members of the GTDB team to respond to your other questions.


Hi Donovan,
Thank you for your swift reply! Looking forward to other answers.

And thank the GTDB team for your contribution to the classification of bacteria and archaea. Thank you for maintaining this forum which is very helpful! Many more thanks to the time and efforts you and the GTDB team have been paid for!