The phylum Elusimicrobia previosuly known as 'Termite Group 1' has been shown to be widespread in different ecosystems like marine environment, sewage sludge, contaminated sites and soils. The high abundance of 'Elusimicrobia' representatives is only evidenced for the lineage of symbionts found in termites.

The first organism to be cultured was Elusimicrobium minutum

Elusimicrobium minutum

Elusimicrobium minutum is an ultramicrobacterium and first accepted member to be cultured of a major bacterial lineage previously known only as candidate phylum Termite Gut 1 , which has accordingly been renamed phylum Elusimicrobia....

, however other two species has being partially described and placed in a seperate class, known as Endomicrobia.

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LSPN)

and the phylogeny is based on 16S rRNA-based LTP release 106 by The All-Species Living Tree Project 
Notes:
♥ Strains not lodged at National Center for Biotechnology Information

National Center for Biotechnology Information

The National Center for Biotechnology Information is part of the United States National Library of Medicine , a branch of the National Institutes of Health. The NCBI is located in Bethesda, Maryland and was founded in 1988 through legislation sponsored by Senator Claude Pepper...

 (NCBI) and or listed in the List of Prokaryotic names with Standing in Nomenclature (LPSN)