The first representatives of the millipede family Glomeridellidae (Diplopoda, Glomerida) recorded from China and Indochina

A new species of glomeridellid millipede is described from Guizhou Province, southern China: Tonkinomeris huzhengkunisp. nov. This new epigean species differs very clearly in many structural details, being sufficiently distinct morphologically and disjunct geographically from T. napoensis Nguyen, Sierwald & Marek, 2019, the type and sole species of Tonkinomeris Nguyen, Sierwald & Marek, 2019, which was described recently from northern Vietnam. The genus Tonkinomeris is formally relegated from Glomeridae and assigned to the family Glomeridellidae, which has hitherto been considered strictly Euro-Mediterranean in distribution and is thus new to the diplopod faunas of China and Indochina. Tonkinomeris is re-diagnosed and shown to have perhaps the basalmost position in the family Glomeridellidae. Its relationships are discussed, both morphological and zoogeographical, within and outside the Glomeridellidae, which can now be considered as relict and basically Oriental in origin. Because of the still highly limited array of DNA-barcoding sequences of the COI mitochondrial gene available in the GenBank, the first molecular phylogenetic analysis of Glomerida attempted here shows our phylogram to be too deficient to consider meaningful.