The family Thermodesulfobiaceae according to the

LPSN List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomica ...

is located within the order Thermoanaerobacterales and class

Clostridia The Clostridia are a highly polyphyletic class of Bacillota, including ''Clostridium'' and other similar genera. They are distinguished from the Bacilli by lacking aerobic respiration. They are obligate anaerobes and oxygen is toxic to them. S ...

. However, according to the

All-Species Living Tree Project The All-Species Living Tree' Project is a collaboration between various academic groups/institutes, such as ARB, SILVA rRNA database project, and LPSN, with the aim of assembling a database of 16S rRNA sequences of all validly published species ...

it lies outside the clade

Bacillota The Bacillota (synonym Firmicutes) are a phylum of bacteria, most of which have gram-positive cell wall structure. The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earl ...

and the genus '' Caldanaerovirga'' does not belong to the clade, i.e. Thermodesulfobiaceae is

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...

Phylogeny

This family formerly included two genera ('' Thermodesulfobium'' and ''

Coprothermobacter ''Coprothermobacter'' is a genus of rod-shaped microorganisms, belonging to the new bacterial family ''Coprothermobacteraceae'' of the new phylum ''Coprothermobacterota''. This taxonomic genus has been reclassified in 2018, after different phylog ...

''); however, the taxonomy of this family is under review because the genus ''

'' was excluded from this family in March 2018, after several genomic analyses confirmed the differences between them. The most recent classification updates are already reported by the

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The ...

(NCBI), even though some taxonomy considering former versions of the

List of Prokaryotic names with Standing in Nomenclature List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the nomenclature, naming and Taxonomy (biology), taxonomy of prokaryotes, following the taxonomy requirements and rulings of the In ...

(LPSN), or old releases of 16S rRNA-based tree from

The All-Species Living Tree Project The All-Species Living Tree' Project is a collaboration between various academic groups/institutes, such as ARB, SILVA rRNA database project, and LPSN, with the aim of assembling a database of 16S rRNA sequences of all validly published species ...

. may still include it.

References

*Thermodesulfobiaceae {{clostridia-stub