Tasmaniosoma clarksonorum, Mesibov, 2010

Mesibov, Robert, 2010, The millipede genus Tasmaniosoma Verhoeff, 1936 (Diplopoda, Polydesmida, Dalodesmidae) from Tasmania, Australia, with descriptions of 18 new species, ZooKeys 41 (4), pp. 31-80 : 52-53

Tasmaniosoma clarksonorum sp. n.

urn:lsid:zoobank.org:act:F8AE3AE0-B587-4720-B41A-CFCD5EE353EA

Figs 1B, 1F, 10B; map Fig. 25

Holotype. Male, Australia, Tasmania, Mt Barrow , 41°21'33"S 147°24'54"E ( EQ 346211) ± 100 m, 740 m, 1 August 2005, W. & L. Clarkson, under bark on Eucalyptus , QVM 23 :46584.

Paratypes. 10 males, 2 females, 1 stadium VI female, details as for holotype, QVM 23 : 46583 ; 9 males, 5 females, details as for holotype but 41°21'30"S 147°24'24"E ( EQ 339212) ± 100 m, 750 m, QVM 23 :46582 .

Other material examined. 80 males and 17 females from 28 other sites (see Appendix).

Diagnosis. Metatergites with three transverse rows of large, low, contiguous tubercles; leg 7 sternal tab with dense brush of stout, rod-like setae; gonopod telopodite with central, flattened process notched into three parts and two combs of long, stout, rodlike setae on posterior surface, the distal comb directed distally and the much smaller basal comb directed basally.

Description. Male/female approximate measurements: length 11/ 11 mm, ring 12 paranota width 1.4/ 1.5 mm. Live and freshly preserved males with head violet dorsally; antennae purplish-brown; legs pale, reddish distally; paranota with reticulate red pattern (Fig. 1B); prozonites dorsally brown, darker laterally and posteriorly, with small paramedian pale yellow patches, arcuate or semicircular, in posterior half; metazonites dorsally with paramedian pale yellow patches on waist contrasting with dark brown colouring medially and laterally, and metatergites light brown with darker patches bordering paranota, and paramedian pale yellow spots in posterior half; laterally (Fig. 1F) a mottled brown on metazonites below paranota and on prozonites, pale yellow on metazonites just posterior to suture; ventrally with pale yellow prozonites and light brown sternites. Female live colouring similar, but with pale yellow patches more distinct, and with median longitudinal dark brown band dorsally on metazonites. In alcohol, long-preserved specimens light brown with reddish markings laterally on metatergites.

Most non-gonopod details as for T. armatum , but antennomeres 3 and 6 equal in length and longest, relative widths tergite 6>5>(4,head)>(3,2)>collum, ring 12 paranota 1.3 × as wide as prozonite, leg 6 tarsus 2 × as long as femur, prefemur not as swollen. Anterior margin of metatergite smoothly curving into lateral edge of paranota (shoulder less distinct than in T. armatum ); metatergite almost completely covered with three transverse rows of 10–12 large, low tubercles, each with small seta near pos- terior edge. Ring 2 pit with rim only defined anteriorly and laterally. Ring 6 sternite with no leg 6 tab; leg 7 tab long, thickened, with row of fine setae on anterior surface; sparse row of fine setae on anterior sternal margin.

Gonopod telopodite (Fig. 10B) straight, subcylindrical, divided at slightly more than 3/4 telopodite height into apical cluster of three major processes: (a) short, rodlike, slightly curved, acute solenomere medially; (b) long, rod-like, acute and slightly sinuous lateral process, directed laterally before abruptly turning distal; (c) broad, flattened central process between (a) and (b), deeply notched to produce blade-like, curved anterolateral branch, slender, acute central branch and rounded, tab-like posteromedial branch. In addition, very short, stout process arising just anterior to solenomere base and directed anteromedially, the tip notched. Closely packed row of 15–20 stout, rodlike, distally directed setae on distal side of oblique thickening on the posterior surface, the row running from a point basal to solenomere origin distolaterally to a point basal to lateral process origin; cluster of 5–10 stout, rod-like setae arising at ca 1/2 telopodite height on posterolateral surface and directed posterolaterally and slightly basally; and sparse fine setae on posterolateral surface to ca 1/3 telopodite height. Prostatic groove running more or less straight base of solenomere on medial surface.

Female more robust than male and with distinctly shorter midbody metatergites, width:length 3.0 in female vs 2.3 in male.

Distribution. Often locally abundant in cool temperate rainforest and wet eucalypt forest over ca 2000 km 2 in northeast Tasmania from ca 250 m to at least 1000 m elevation ( Fig. 25 ). Occurs west almost to Lilydale, north and east to the Weldborough area, and south to Mt Stewart between Epping Forest and Avoca. Th e southern outlier on Mt Stewart may not be a disjunct population; the forests between this T. clarksonorum locality and the more northern ones have not yet been carefully surveyed for millipedes. Sympatric with T. decussatum sp. n. and T. gerdiorivum sp. n., parapatric with T. armatum on Mt Barrow and near Weavers Creek, and possibly parapatric with T. cacofonix sp. n. in the east of the T. clarksonorum range.

Etymology. In honour of Tasmanian field naturalists Wade and Lisa Clarkson, who enthusiastically searched for this and other Tasmaniosoma species in 2005 and 2006.

Figures

Figure 25. A Localities as of 31 January 2010 for Tasmaniosoma barbatulum sp. n. (squares), T. clarksonorum sp. n. (crosses), T. decussatum sp. n. (open circles) and T. fragile sp. n. (triangles). See also Figs 23 and 26. Scale bar = 50 km. B Map of Tasmania showing location of main map (rectangle).