AbstractTheCampylobacterotais a novel phylum created from the reclassification of the proteobacterial classEpsilonproteobacteriaand orderDesulfurellales(Deltaproteobacteria). The phylum is organized according to phylogenies based on a concatenated alignment of 120 conserved protein marker sequences and the 16S rRNA gene. Like any phylogenetic inference, this road map is a hypothesis based on the data available at the time of writing and may be subject to change as new species are described, or other gene sequences considered. This road map incorporates relative evolutionary divergence to normalize subordinate ranks. It, therefore, includes a number of changes at the rank of order, family, and genus, which would otherwise not be affected by the merging of the former lineages.