Chaleponcus ibis, Enghoff, 2014

Enghoff, Henrik, 2014, A mountain of millipedes I: An endemic species-group of the genus Chaleponcus Attems, 1914, from the Udzungwa Mountains, Tanzania (Diplopoda, Spirostreptida, Odontopygidae), European Journal of Taxonomy 100, pp. 1-75 : 44-46

Chaleponcus ibis sp. nov.

urn:lsid:zoobank.org:act:E6764255-8F2F-4B2D-8F3C-26F40FA01EB0

Figs 9 , 22

Diagnosis

Large. Gonopod coxa ( Fig. 9 ) without a lateral process; metaplical shelf-spine very long. Telomere with a rugged anterior lamella and posterior lamella ending in short, parallel, elongate lobes. Claws of walking legs surrounded by ‘palisade’ of setae, a character shared only with C. circumvallatus sp. nov.

Etymology

The name is a noun in apposition and refers to the somewhat ibis bill-like metaplical shelf-spine.

Material studied (total: 1 ♂)

Holotype

TANZANIA: ♂, Iringa Region, Iringa District, Udzungwa Mts, West Kilombero FR, Udekwa village , Nyambanito Mt. , Ukami Forest , 07° 42’49” S, 36°25’15” E, Jul.–Nov. 1994. D. Moyer leg. ( ZMUC).

Type locality

TANZANIA: Iringa Region, Iringa District, Udzungwa Mts, West Kilombero FR, Udekwa village, Nyambanito Mt., Ukami Forest, 07° 42’49” S, 36°25’15” E.

Description (male)

DIAMETER. 3.5 mm, 54 podous rings (the largest of all species in the group).

COLOUR. After 20 years in alcohol ground colour greyish, posterior part of metazonites yellow-brownish; traces of a broad dorsal dark stripe (most other species have traces of a light stripe).

ANAL VALVES. Each with a strong, apparently broken dorsal and smaller, but well-developed ventral spine. Margin raised, setiferous tubercles on ravelins.

LIMBUS. With triangular lobes; lobes ca. as long as wide, margin micro-dentate, outer surface striate.

TARSAL SETATION. Unusual: claws surrounded and almost hidden by numerous stiff setae, accessory claw much longer than claw (as in C. circumvallatus sp. nov., Fig. 5B, C ).

GONOPOD COXA ( Figs 9 , 22 ). Stout, ca. 3 × as long as wide. Lateral margin irregularly convex, continuing in smooth curve in apical margin; cucullus (cu) hence regularly rounded. Metaplica posterio-mesally with triangular process (mp). Metaplical shelf (ms) relatively small, giving rise to very long, slightly curved metaplical shelf-spine (mss). GONOPOD TELOPODITE ( Fig. 22 ). Solenomere with a very long, straight, mesad proximal spine (ps).

Telomere distally with two branches, both curving anteriad:

• an irregular shaped anterior lamella (al) with coarsely dentate proximal part and a smooth, subrectangular distal part (which maybe corresponds to the accessory lobe, al’¸ in C. circumvallatus sp. nov.),

• a posterior lamella (pl) ending in two short, parallel, elongate lobes.

Distribution and habitat

Known only from Nyambanito Mt. in West Kilombero Scarp FR. No altitude or habitat information.

Coexisting species

C. basiliscus sp. nov. was found in the same sample as C. ibis sp. nov. In addition, C. circumvallatus sp. nov., C. gracilior sp. nov., C. netus sp. nov. and C. tintin sp. nov. were found in West Kilombero Scarp FR.

Notes

Resembles the almost similar-sized C. circumvallatus sp. nov. both in the unusual tarsal setation and in gonopod structure. C. ibis sp. nov. differs from C. circumvallatus sp. nov., i.a., in having distinct lobes on the limbus, in having the metaplical shelf-spine (mss) much longer, in having the proximal part of the anterior telomeral lobe (al) coarsely dentate, and in having two relatively short, parallel elongate lobes on the posterior telomeral lamella, as opposed to the two very long, diverging spines in C. circumvallatus sp. nov.

Figures

Fig. 9. Chaleponcus spp., outline of coxite of left gonopod, posterior view. (The ’transverse’ plane of the gonopod is usually slightly at angles with the exact transverse plane of the millipede, so it may be necessary to tilt the gonopod slightly in order to obtain the view shown on the drawings.) The stippled lines indicate the place where the telopodital basomere emerges from the coxal cavity. Not to scale.

Fig. 22. Chaleponcus ibis sp. nov., left gonopod. A. Posterior view. B. Anterior view. C. Telopodite, mesal-anterior view. al = anterior lobe of telomere, al’ = accessory lamella?, cu = cucullus, mp = mesal metaplical process, ms = metaplical shelf, mss = metaplical shelf-spine, pl = posterior lobe of telomere, ps = proximal spine of solenomere. Scales 0.1 mm.

Fig. 5. Chaleponcus spp., tip of tarsus and claw of walking legs. — A. C. mwanihanensis sp. nov. as an example of normal setation. B–C. C. circumvallatus sp. nov. with the claw surrounded by a ’palisade’ of setae. Scales 0.1 mm.