Asphalidesmus magnus, Mesibov, Robert, 2011

Mesibov, Robert, 2011, New species of Asphalidesmus Silvestri, 1910 from Australia (Diplopoda, Polydesmida, Dalodesmidea), ZooKeys 93, pp. 43-66 : 49-51

Asphalidesmus magnus sp. n. Figs 1D, 1F2C710A, 10B, 10Cmap fig. 12

Holotype.

Male, Mt Haig, Lamb Range, Qld, 17°05'52"S, 145°36'09"E ± 0.5 km, 1000 m, 25 February 1997, G. Monteith, QM berlesate 918, rainforest, leaf litter, ex QM S37557, QM S90025.

Paratypes.

5 males, 5 females, details as for holotype, QM S90026.

Other material.

(All from Qld) 2 males, 2 females, Cammoo Caves near Rockhampton (see Distribution), 23°10'S, 150°28'E ± 1 km, 25 October 1976, R.W. Taylor and T.A. Weir, ANIC berlesate 535, dense low closed forest, ANIC 64-000204; 1 male, 1 female, 3 km W by S of Mt Haig, Lamb Range, Qld, 17°06'S, 145°34'E ± 1 km, 1150 m, 3 April 1984, A. Calder and T.A. Weir, ANIC berlesate 952, rainforest, ANIC 64-000203; 1 male, Lambs Head, 10 km W of Edmonton, 17°01'23"S, 145°38'33"E ± 0.5 km, 1200 m, 4 December 1988, G. Monteith and G. Thompson, QM berlesate 806, rainforest, sieved litter, QM S90028; 2 males, Vine Creek, Majors Mountain, 17°40'58"S, 145°32'02"E ± 0.5 km, 1050 m, 5 February 1999, G. Monteith and D. Cook, QM berlesate 987, rainforest, sieved litter, QM S90027.

Diagnosis.

Dorsum distinctly flattened anteriorly; 2 small, rounded, paramedian swellings dorsally on rings 16-18; 3 transverse rows of tubercles on midbody metatergites; gonopod telopodite with posteriorly curving anterior branch and Y-shaped posterior branch directed posterodistally and slightly laterally.

Description.

Males and females approximately the same size, length ca 5 mm, ring 6 vertical diameter ca 0.6 mm and maximum width ca 1.1 mm. Body strongly tapered from wide head to narrow telson (Fig. 1D); dorsum flattened anteriorly (Figs 1F, 10C); rings 16-18 with 2 small, rounded, paramedian swellings on (meta)tergites (Figs 10A, 10B). Midbody metatergites with 3 transverse rows of tubercles dorsally. Paranota wide (Fig. 1F); anterior and lateral margins in single convex curve, posterior margin straight; 3-4 weakly defined marginal lobes.

Gonopod telopodite (Figs 2C, 7) more or less cylindrical, tapering distally from laterally extended base, with a few strong setae on posterior surface, divided at ca three-quarters telopodite height into anterior and posterior branches. Anterior branch somewhat flattened anteroposteriorly, with the lateral margin extended as rounded triangle basally; branch directed distally but curving posteriorly, the tip spade-like, pointed and slightly thickened. Posterior branch flattened mediolaterally, directed posterodistally and slightly laterally; branch Y-shaped, divided at ca one-half branch length into thin arms, one directed distally and the other laterally, both arms tipped with minute, variably positioned processes. Prostatic groove on anteromedial surface of telopodite, following posterior branch and terminating at tip of distally directed arm.

Distribution.

Known from tropical rainforest in far north Queensland and from a single collection near Cammoo Caves in central coastal Queensland (Fig. 12). Cammoo Caves are ca 840 km from the type locality of Asphalidesmus magnus , but the four specimens from the Caves differ from the types mainly in being marginally larger; the gonopods are almost identical. If the specimens are indeed from forest near the Caves, then Asphalidesmus magnus may have been accidentally introduced to the area from far north Queensland. This record needs to be checked by further sampling in the Cammoo Caves area.

Etymology.

Latin magnus, ‘large’, the name also containing Latin agnus, ‘lamb’. Asphalidesmus magnus is the larger of the two Asphalidesmus species found on the Lamb Range.

Remarks.

Asphalidesmus magnus can coil tightly in a spiral.

The dorsal flattening seen in this species (Figs 1F, 10C) contrasts strongly with the smoothly rounded cross-section of the type species Asphalidesmus leae (Figs 1E, 10D). Further, limbus elements in Asphalidesmus magnus are noticeably longer and more slender than limbus elements in the other nine Asphalidesmus spp. (Fig. 11) As the difference is only detectable at very high magnification, and because elements vary in length and width around the circumference of a body ring, I am reluctant to include this character state in the species diagnosis.

Latitude/longitude data in italics are from the QM collection database.