Tholerosoma corrugatum, Mesibov, Robert, 2006

Mesibov, Robert, 2006, Dirt-encrusted and dragon millipedes (Diplopoda: Polydesmida: Paradoxosomatidae) from Queensland, Australia, Zootaxa 1354, pp. 31-44 : 42-43

Tholerosoma corrugatum n. sp.

Figs. 5 B, 5C, 5F, 6A, 6C; map Fig. 7

Holotype: Male, Mt Elliot summit , 19°30’S 146°57’E, 1150 m, January to 26.iii.1991, A. Graham, fern glade, pitfall & intercept, QM S73993 .

Paratypes: Male, Stony Creek, track crossing , 21°37’S 148°59’E, 280 m, 4.x.–17.xii.1999, D. & I. Cook, rainforest, pitfall, sample 9030, QM S73994 ; female, Bluewater Range , 45 km WNW of Townsville, 19°12’S 146°24’E, 600–700 m, 6–8.xii.1986, G. Monteith, G. Thompson & S. Hamlet, QM S73995 ; stadium VII female, Mt Hayward , 20°20’S 148°45’E, 350 m, 19–20.xi.1992, G. Monteith, G. Thompson, D. Cook & H. Janetzki, QM S73996 ; female, Palm Island site 1 , 18°45’S 146°36’E, 450 m, 21.ii.2001, G. Monteith, rainforest, sample 8323, QM S73997 .

Diagnosis: Distinguished from T. monteithi by having 6 small swellings on posterior edge of metatergite, rather than 2 large paramedian swellings on either side of transverse furrow; distal portion of telopodite curving towards base; and spiracles without plate-like structures on surface.

Description: As for T. monteithi , but in overall size at the lower end of the T. monteithi range. Collum and metatergites with 6 small, oblong swellings on posterior edge, often hidden by encrusting dirt ( Figs. 5 F, 6A). Longitudinal corrugations at waist not as long or as deep as in T. monteithi . Spiracles protruding, densely filled with extremely minute, blunt processes as in T. monteithi , but without plate-like structures on surface ( Fig. 6 C). Distal portion of gonopod telopodite tapering gradually, curving towards base after abrupt lateral turn; tip pointed towards base in holotype ( Fig. 5 B).

Distribution and habitat: Known from five sites in tropical rainforest from Palm Island north of Townsville to the Mackay area in north Queensland, an approximate linear range of 430 km and an elevation range of 280–1150 m. Sympatric with T. monteithi in the Bluewater Range near Townsville.

Etymology: Latin corrugatus (“ridged”), from the appearance of the posterior edge of the metatergite.

Remarks: Only two males of T. corrugatum are known, from sites more than 350 km apart, and while the specimens agree in other details, the tip of the telopodite turns distally in the paratype ( Fig. 5 C). The two nominal species of Tholerosoma are most easily distinguished by the absence of large paramedian swellings in T. corrugatum . The sympatry of the two species is probably syntopy: both were taken at a single collecting site in the Bluewater Range in 1986.

Figures

FIGURE 5. Tholerosoma monteithi n. gen., n. sp. (A) medial view of right gonopod, (D) antenna, (E) leg 6 (male paratype, QM S 73974). Tholerosoma corrugatum n. sp. (B) medial view of right gonopod (holotype, QM S 73993), (C) medial view of right gonopod (male paratype, QM S 73994), (F) outline sketch of midbody metazonite, showing location of swellings on posterior edge (female paratype, QM S 73995). Setation not shown; dashed lines in (A) – (C) indicate course of prostatic groove. Scale bars for (A) – (C) and for (D) and (E) = 0.25 mm.

FIGURE 6. Tholerosoma corrugatum n. sp. (A) dorsal view of midbody ring, (C) spiracles on midbody ring, anterior to left (holotype, QM S 73993). Tholerosoma monteithi n. gen., n. sp. (B) anterior spiracle on midbody ring, anterior to left (male paratype partly cleaned with ultrasound, QM S 73975). Scale bar for (A) = 0.5 mm, for (B) and (C) = 0.1 mm.

FIGURE 7. Localities for Desmoxytoides hasenpuschorum n. gen., n. sp. (left, squares), Tholerosoma monteithi n. gen., n. sp. (centre, triangles) and T. corrugatum n. sp. (centre, stars). Rectangle in Australia map (right) shows boundary of main maps.