Integrative description and phylogenetic position of a rare species Diphascon birklehofi (Eutardigrada: Hypsibiidae)

An integrative redescription of the rare tardigrade species Diphascon birklehofi, based on the morphological reinvestigation of the type material and first molecular data for a population discovered in freshwater sediments in the vicinity of Saint Petersburg, is given. The analysis of obtained nucleotide sequences of nuclear and mitochondrial DNA markers revealed an unexpected position of the species. A new phylogeny reconstruction for the family Hypsibiidae based on the new data is presented and discussed.