Phylogenetic relationships of Siliquobolellus gen. nov. and several other spirobolidan millipede taxa based on maximum likelihood analysis (ML) and Bayesian inference (BI) of a 660 bp COI gene fragment. Numbers at nodes indicate branch support based on bootstrapping (ML) / posterior probabilities (BI). Scale bar = 0.3 substitutions/site. # indicates branches with < 50% ML bootstrap support or < 0.95 posterior probability, - indicates non-supported branches. The colored areas mark the families Pseudospirobolellidae (minus Benoitolus) (purple) and Pachybolidae (plus Benoitolus) (yellow).