Pyrgodesmus Pocock, 1892

Golovatch, Sergei I., 2021, Identity of the millipede genus Pyrgodesmus Pocock, 1892, the type genus of the family Pyrgodesmidae (Diplopoda, Polydesmida), Zootaxa 5068 (4), pp. 572-578 : 573-577

Genus Pyrgodesmus Pocock, 1892

Type-species: Pyrgodesmus obscurus Pocock 1892 , by monotypy.

Other species included: Pyrgodesmus permutatus ( Attems, 1936) , comb. nov.

Diagnosis of Pyrgodesmus

Pyrgodesmus seems to be particularly similar to Klimakodesmus in most somatic characters, as correctly noted by Carl (1932) and recently reinstated by Aswathy et al. (2021). Yet both genera are distinct primarily in gonopodal structure: hypertrophied coxites, a deep gonocoel and ribbon-shaped, unipartite, distally attenuating, but not acuminate telopodites ( Figs 5–8 , 29 & 30 ), vs. moderately incrassate, apparently smaller, subspherical or squarish coxites, 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 conceals the epiproct from above, are much higher and stronger, whereas DL reduced, in Pyrgodesmus compared to Klimakodesmus species ( Aswathy et al. 2021).

Figures

FIGURES 1–8. Pyrgodesmus obscurus Pocock, 1892, male syntypes. 1. Original labels. 2. Both syntypes pierced with glass minutiae, shown relative to the length of an insect pin. 3. Habitus of a syntype, lateral view (after Pocock (1892)). 4. Picture of the same, lateral view. 5. Body rings 5–7 and gonopods in situ, ventral view. 6. Body rings 6–9 and gonopods in situ, ventrolateral view. 7 & 8. Enlarged gonopods in situ, ventral and ventrolateral views, respectively. Figs 1–3, 7 and 8 not to scale. Images courtesy Dmitry Telnov.

FIGURES 19–30. Pyrgodesmus permutatus (Attems, 1936), comb. nov., male syntype. 19. Head, dorsal view. 20. Anterior part of body, ventral view. 21. Antenna, lateral view. 22. Gnathochilarium, ventral view. 23. Anteromedial part of gnathochilarium, ventral view. 24. Right paraterga 11 and 12, dorsal view. 25. Cross-section of body ring 8, posterior view. 26. Posterior part of body, ventral view. 27. Fine structure of limbus, dorsal view. 28. Leg of body ring 8. 29. Left gonopod, mesal view. 30. Telopodite of right gonopod, mesal view. All after Silvestri (1920), drawn not to scale.