Identity of the millipede genus Pyrgodesmus Pocock, 1892, the type genus of the family Pyrgodesmidae (Diplopoda, Polydesmida)
Author
Golovatch, Sergei I.
text
Zootaxa
2021
2021-11-18
5068
4
572
578
journal article
3390
10.11646/zootaxa.5068.4.6
79b5ca84-737c-4722-9994-9f5cdefbebb3
1175-5326
5709642
E4A3743F-14A9-4292-AC55-56B7E7F0905C
Genus
Pyrgodesmus
Pocock, 1892
Type-species:
Pyrgodesmus obscurus
Pocock 1892
, by monotypy.
Other species included:
Pyrgodesmus permutatus
(
Attems, 1936
)
,
comb. nov.
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 9–18.
Pyrgodesmus permutatus
(
Attems, 1936
)
,
comb. nov.
, habituses of two male syntypes, one coated with earth (10–12) and the other clean (13–18). All after
Silvestri (1920)
, drawn not to scale.
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.
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
).