Koponenius, Golovatch, Sergei I. & Vandenspiegel, Didier, 2014

Golovatch, Sergei I. & Vandenspiegel, Didier, 2014, Koponenius gen. nov., a new genus of the millipede family Haplodesmidae from the Himalayas of India and Nepal (Diplopoda: Polydesmida), Zootaxa 3894 (1), pp. 141-151 : 142-144

Koponenius gen. nov.

Name: Honours Seppo Koponen, a prominent colleague arachnologist from Turku University, Finland, on the occasion of his 70th birthday; masculine in gender.

Diagnosis: Differs from the other 6 known haplodesmid genera by only 19 body segments in both sexes, combined with a rather pyrgodesmid-like body shape and a special ozopore formula (5, 7–18), ozopores being borne on porosteles, as well as 4 transverse rows of setigerous isostictic tubercles per postcollum metatergum and a clearly helicoid, twisted prefemoral portion of the gonopod so that the seminal groove runs mostly laterally, not mesally (see also Key below).

Description: Body with 19 segments in both sexes, subcylindrical, not capable of volvation. Head, collum and following metaterga clothed with a dense cerategument. Ozopores borne on simple porosteles, pore formula 5, 7–18. Collum relatively large, sometimes covering the head from above. Paraterga 2 considerably enlarged, but not so as to ensure complete volvation, instead subtending the head laterally. Each postcollum metatergum usually with 4 transverse rows of isostictic setigerous tubercles. Telson strongly flattened dorsoventrally, subtruncate at tip, fully concealing a small epiproct tip from above. Spiracles seem to be absent.

Gonopods of a facies rather typical of Haplodesmidae , in situ both held nearly parallel to each other: coxae elongate, non-globose, subcylindrical, both well fused anteromedially, each carrying an elongated cannula on mesal face; telopodites elongated, slender, each clearly subdivided into an elongated, clearly helicoid, twisted prefemoral (= densely setose) part on which the seminal groove runs mostly laterally, not mesally; acropodites curved caudad, slender, uni- or biramous; seminal groove borne on a long solenomere, terminating apically, devoid both of an accessory seminal chamber and a hairy pulvillus.

Type species: Koponenius unicornis sp. nov.

Other species included: Koponenius biramus sp. nov.

Remarks: The family Haplodesmidae hitherto contained six genera. Most of them can be conveniently divided into two morphological groups: (1) The “haplodesmid” type usually shows ozopores borne on special, mostly boletiform porosteles or tubercles, while paraterga are absent from body segment 3 onwards, and (2) The “doratodesmid” type is normally devoid of porosteles, whereas the paraterga are present on all segments, often ensuring complete volvation ( Golovatch et al. 2009a).

Koponenius gen. nov. seems to be especially similar to Prosopodesmus Silvestri, 1910 , likewise being intermediate between the two groups described above in showing quite strongly developed paraterga, coupled with the presence of porosteles. However, all 7 known Prosopodesmus species (mostly native to tropical Australia, but a few to southern Japan) are considerably more pyrgodesmid-like in body shape, the collum being strongly flabellate, its fore margin 12-lobulated, covering the head from above. In addition, they have 20 body segments, only 3 transverse rows of isostictic tubercles per postcollum metatergum, varying pore formulas, but not (5, 7–18), usually mushroom-shaped porosteles, and the seminal groove on falcate and unbranched gonopod telopodites which runs only on the mesal side and is typically supplied with a hairy pulvillus near its orifice ( Mesibov 2012). The above similarities between these two genera are also reflected in an updated key which concludes this paper.