<unk>  is a taxon created by Cavalier-Smith, which includes several groups of Gram-negative bacteria. In this model, it is the ancestor of gram positive bacteria. Their endospores are characterized by producing and presenting external flagella or mobility by bacterial displacement.
Eurybacteria
Streptococcus
Nontuberculous mycobacteria
Enterococcus
Yeast
Actinobacillus
Fusobacteriota
Lactobacillus