Klimakodesmus Carl, 1932

Sudhikumar, Ambalaparambil Vasu, 2021, The millipede genus Klimakodesmus Carl, 1932, with the description of a new species from Kerala state, southern India (Diplopoda, Polydesmida, Pyrgodesmidae), Zootaxa 4980 (2), pp. 373-382 : 375

Genus Klimakodesmus Carl, 1932

Type-species: Klimakodesmus gravelyi Carl, 1932 , by monotypy.

Other species included: Klimakodesmus bilobocaudatus sp. nov.

Brief description. This genus shows a body shape and an ornamentation pattern typical of Pyrgodesmidae , characterized by 20 segments/rings (19+T) both in the male and female; a flabellate collum is strongly domed and tuberculate, completely covering the head from above, with 5+5 distinct, equal, clearly incised and rounded lobulations at a subhorizontal anterior margin; the antennae are short, two basal antennomeres of each antenna being sunken inside a distinct transverse groove, and antennomere 5 being much longer and thicker than the 6 th; a cerotegument crust with microvilli covers most of the dorsal surface of the collum and following metaterga, the limbus being microlobulate and microspiculate caudally; body rings are strongly arched dorsally, each with 2+2 longitudinal rows of basically 2+2 or 3+3 larger and fused tubercles/lobes (paramedian, PM, and dorsolateral, DL), both rows largely representing higher bilobed keels mostly slightly inclined either forward or caudad, but PM always being higher than DL. PM of only ring 19 is abruptly and unusually strongly elongate and more or less clearly bilobate caudally, conspicuously overhanging and concealing a short epiproct from above ( Figs 2–4 , 8–10 ). Neither intercalary (i) series of grains nor antero- (Am), nor truly caudomarginal lobulations (Cm) are distinguished. The pore formula is normal: ozopores 5, 7, 9, 10, 12, 13, 15 and 16 are borne on distinct porosteles, vs. 17, 18 and 19 which open flush on the surface. The paraterga are set low (at about half the height of midbody metazonae), slightly declivous to subhorizontal, leaving the dorsum very convex, moderately bi- or trilobate laterally regardless of a cylindrical porostele or ozopore located just before or upon the ultimate lobulation, respectively. The legs are short and stout, rather sparsely setose, the prefemur bearing a particularly strong seta distomesally, the tibia a distodorsal one.

The gonopods are fairly simple, in situ either slightly diverging or distally crossing each other; each coxite is moderately enlarged, hemispherical or squarish, microgranulate and microsetose laterally, and concave medially, the gonocoel thus being moderately deep; the cannula is as usual, simple, moderately long and strongly unciform. The telopodite is simple, slender, unipartite, represented by a very strong, moderately long, but mostly exposed, gradually attenuating and acuminate solenomere.

Diagnosis. Klimakodesmus seems to be particularly similar to Pyrgodesmus in most somatic characters, as correctly noted by Carl (1932), but both genera are distinct primarily in gonopodal structure: clearly hypertrophied gonocoxites and “blade-like” telopodites ( Pocock 1892) vs. moderately incrassate, apparently smaller, subspherical or squarish gonocoxites, each of which supports a strong and unipartite telopodite represented solely by a slender, strongly exposed, increasingly attenuating and acuminate solenomere. In addition, PM crests, including the one on the penultimate ring that overhangs and fully conceals the epiproct from above, are much higher and stronger, whereas DL reduced, in Pyrgodesmus compared to Klimakodesmus species.

A similar, remarkably strong, massive and largely exposed solenomere taking up most of the gonopod telopodite is also observed in the genus Pseudocatapyrgodesmus Miyosi, 1957 , with P. glaucus Miyosi, 1957 , the type species from Honshu, Japan ( Miyosi 1957), and P. pulcher Golovatch, Semenyuk, VandenSpiegel & Anichkin. 2011 , from southern Vietnam ( Golovatch et al. 2011). Yet their gonopods are considerably more elaborate and clearly branched, vs. relatively very simple and unipartite in Klimakodesmus . They are the gonopods of P. pulcher that seem to be especially similar to those of Klimakodesmus ( Golovatch et al. 2011) .

The strong, flattened, dorsal crest PM on the penultimate ring that overhangs and conceals the epiproct from above, however conspicuous, is unique to neither Klimakodesmus nor Pyrgodesmus species. For instance, several, but not all of the Afrotropical species of the genera Monachodesmus Silvestri, 1927 or Udodesmus Cook, 1896 show the same or very similar conditions ( Golovatch et al. 2015, 2017).

Figures

FIGURES 1–4. Klimakodesmus bilobocaudatus sp. nov. 1. Natural microhabitat (rotting wood with a colony on the surface, photographed not to scale). 2. Adult male paratype, dorsal view. 3. Subadult female paratype, lateral view. 4. Adult male paratype, ventral view.

FIGURES 8–15. Klimakodesmus bilobocaudatus sp. nov. 8. Posterior half of body (subadult female paratype), lateral view. 9 & 10. Posterior part of body (adult male paratype), dorsal and ventral views, respectively. 11. Midbody leg (adult male paratype), lateral view. 12–14. Both gonopods (adult male paratype), caudal, oral and caudal views, respectively. 15. Right gonopod, caudal view. Abbreviations: cx, coxite; lo, mesal lobe; sl, solenomere. NB: Figures 14 & 15 drawn not to scale.