Polydrepanum implicatum Carl, 1941

Golovatch, Sergei I., Aswathy, Mathilakath Dasan, Bhagirathan, Usha & Sudhikumar, Ambalaparambil Vasu, 2021, Review of the millipede tribe Polydrepanini, with the description of a new species from Kerala state, southern India (Diplopoda, Polydesmida, Paradoxosomatidae, Alogolykinae), Zootaxa 5068 (4), pp. 485-516 : 491-493

Polydrepanum implicatum Carl, 1941

(= Carlogonopus implicatus ( Carl, 1941)) , comb. nov.

Figs 13–15

Polydrepanum implicatum Carl, 1941: 371 (D). India, Kanda near Bombay.

“ Polydrepanum” (sic!) implicatum — Jeekel, 1965: 128 (R); 1968: 85 (M); 1980b: 175 (M); Bano & Murthy, 1998: 89 (M); Bano, 1998: 89 (M); Golovatch & Wesener, 2016: 48 (M).

Polydrepanum implicatum —Bano, 1997: 12 (M); Nguyen & Sierwald, 2013: 1327 (M).

Telodrepanum implicatum — Sankaran & Sebastian, 2018: 176 , fig. 5B (D).

Remarks. According to Jeekel (1968, 1980a), this species merits a genus of its own. Indeed, in addition to both male femora 1 and 2 showing adenostyles ( Figs 13 and 14 ), the gonopodal femorite (fe) is strongly reduced in size and shows clear evidence of torsion, while the acropodite is tripartite, being divided basally into a dorsal spine (a), a coiled, ribbon-shaped, middle process (r), and the most voluminous ventral piece supporting most of the solenophore (sph), including a midway mesal spine (s) and a subapical mesal spine (b) near an unequally bifid and acuminate tip. The terminal third of sph is strongly unciform, membranous, gradually attenuating distad and directed ventromesad, with a free solenomere (sl) being flagelliform and almost as long as terminal sph third ( Fig. 15 ).

Sankaran and Sebastian (2018) transferred P. implicatum to Telodrepanum , but this was an obvious mistake for the reasons presented below.

On balance, in full agreement with nearly all authors following the original description ( Carl 1941), the above distinctions of P. implicatum from the true, typical Polydrepanum (see above and below) and Polydrepanini generally are sufficiently strong to warrant the erection of a new genus of Alogolykini , Carlogonopus gen. nov. (gender: masculine), to accommodate the type species alone, C. implicatus ( Carl, 1941) , comb, nov. We dedicate the new genus to Johann Carl (1877–1944), the late prominent Swiss specialist in diplopod systematics ( Hollier et al. 2020) who described that species. This new genus is primarily distinguished from all contribal genera by a very short, but still quite discernible gonofemorite (fe), coupled with a flagelliform solenomere (sl) originating distally and sheathed by a prominent and complex solenophore (sph) ( Fig. 15 ). In this respect, the position of Carlogonopus gen. nov. seems to be somewhat intermediate between the tribes Polydrepanini and Alogolykini to bridge both. However, we are inclined to treat the new genus within Alogolykini , because the gonofemorite in C. implicatus is about as short (= strongly reduced) as in Yuennanina , perhaps its closest relative, whereas subflagelliform solenomeres, albeit originating parabasally and obviously stronger, are also observed in Touranella species ( Attems 1936, 1937).

Bhakat (2021) has very recently described a new paradoxosomatid genus and species from Birbhum district, West Bengal state, eastern India: Manikidesmus suriensis Bhakat, 2021. The author assigned that millipede to the tribe Polydrepanini , but unfortunately the description is poor and the images are small and unclear. Because the gonofemorite appears to be considerably shortened, while the acropodite is complex and said to be bipartite, it seems better either to place it closer to Carlogonopus gen. nov. within the tribe Alogolykini or regard it provisionally as a disjunct Delarthrum .

To exacerbate the situation, Manikidesmus suriensis as a name is not available yet for zoological nomenclature, having been proposed in a preprint journal issued only online, while taxonomically the name is a “ nomen nudum ” not registered in ZooBank (like the journal itself).

Figures

FIGURES 13–15. Carlogonopus implicatus (Carl, 1941). 13. Male leg 1, lateral view. 14. Male leg 2, lateral view. 15. Right gonopod, mesal view. After Carl (1941). Abbreviations: a, b and s, basal dorsal (a), subapical mesal (b) and midway mesal spine (s), respectively; ad, adenostyle; fe, femorite; r, coiled ribbon-shaped middle process; sl, solenomere; sph, solenophore. Drawn not to scale.