The Rhynchoproctinae, a south-east Asiatic subfamily of giant millipedes: cladistic analysis, classification, four new genera and a deviating new species from north-west Thailand (Diplopoda : Spirostreptida : Harpagophoridae)

The subfamily Rhynchoproctinae is revised at the generic level. Four new genera and a remarkable new species are described: Alienostreptus, gen. nov. from Vietnam, Armatostreptus, gen. nov., Heptischius, gen. nov., and Heptischius lactuca, sp. nov. from Thailand, and Prominulostreptus, gen. nov. from China. Agaricogonopus Zhang & Zhang, 1997, is removed from synonymy with Junceustreptus Demange, 1961. All 14 genera of the subfamily share three diagnostic gonopodal characters: the posterior surface of the anterior coxal fold forms a deep concavity, there is a mesal flap on the gonopod coxa, and the posterior coxal fold is very low. A cladistic analysis based on morphological data supports monophyly of Rhynchoproctinae and the distincness of the newly described genera. A dichotomous key to the genera is included.