Tasmaniosoma australe, 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 : 44-46

Tasmaniosoma australe sp. n.

urn:lsid:zoobank.org:act:2F05F087-0398-4F19-AFCD-9744B838E2B2

Figs 3D , 6C, 6D , 9 ; map Fig. 24

Holotype. Male, Australia, Tasmania, Lake Osborne Track , 43°13'04"S 146°46'03"E ( DN 810148) ± 100 m, 880 m, 7 February 2004, K. Bonham, QVM 23 :46574.

Paratypes. 3 males, 2 females, details as for holotype but 43°13'07"S 146°45'58"E ( DN 809147) ± 100 m, 900 m, 13 February 2004, QVM 23:46575.

Other material examined. 4 males and 2 females from 4 other localities (see Appendix).

Diagnosis. Metatergites without tubercles, small rounded teeth posterolaterally on paranota, male leg 6 with triangular extension basally on prefemur, solenomere the longest telopodite process, with broad and flattened tip produced as three tooth-like or tab-like extensions.

Description. Male/female approximate measurements: length 18/ 18 mm, ring 12 paranota width 2.2/ 2.2 mm. Live colour not known; in alcohol, body fairly uniform light to medium brown.

Most non-gonopod details as for T. armatum , but antennomere 3 longest, relative widths tergite 6>5>4>2>head>3>collum, ring 12 paranota 1.3 × as wide as prozonite, posterior corners of most paranota produced as very small, rounded tooth, leg 6 tarsus 1.4 × as long as femur and femur longer than prefemur. From ca ring 8 posteriorly, sternites with small, blunt projection at each corner, i.e. just posterior to each of four leg bases. Ring 2 pit deep with well-defined semicircular rim, convex laterally. Ring 6 sternite with sparse fine setae near anterior margin; leg 6 tab barely detectable, with a few fine setae; leg 6 prefemur with rounded triangular extension posteriorly ( Figs 6C, 6D ); leg 7 tab very long (ca 1/2–2/3 length of leg 7 coxa), extending laterad of leg 6 prefemoral swelling, with sparse brush of fine setae basally on anteromedial surface; leg 7 coxa swollen distomedially, the swelling lying posterior to the leg 7 tab.

Gonopod telopodite ( Fig. 9 ) straight, tapering distally, divided into four processes at between 2/3 and 3/4 telopodite height. Undivided portion with posterior surface roundly ridged longitudinally, base laterally extended as rounded protuberance. Processes comprise: (a) short, rod-like, round-tipped anterolateral process bent slightly outwards; (b) short, somewhat flattened posterior process with a rounded-truncate tip bent slightly posteromedially; (c) large solenomere, cylindrical basally, flattening at ca 1/2 process height, curving medially and terminating in rounded tooth apically, with posterior tab carrying opening of prostatic groove and finger-like posterobasal extension; (d) large, rod-like, apically acute process arising just anteromedial to solenomere base and reaching nearly as far distally, slightly bent posterolaterally. Tracts of fine setae posteriorly on either side of the longitudinal telopodite ridge, and on anterolateral surface to ca 1/2 telopodite height. Prostatic groove running distally on medial surface of telopodite to level of division into processes, then running posterolaterally to enter solenomere base.

Female with leg 2 prefemur long and with large swelling distally on posterior surface; rings 2 and 3 ventrally with small, peg-like projection just lateral to epigynum ( Fig. 3D ). Sternite projections as in male but generally smaller, not as consistently expressed.

Distribution. Known from wet eucalypt forest and subalpine scrub to 1240 m elevation in south central Tasmania, extending in a ca 80 km-long line from northwest of Maydena to northwest of Southport ( Fig. 24 ). Possibly parapatric with T. aureorivum sp. n. in the north of its range and with T. warra sp. n. in the south; not yet known to co-occur with either species.

Etymology. Latin australis, “southern”, adjective, for the southern distribution of this species.

Remarks. Females of T. australe are readily distinguished from females of T. aureorivum sp. n. and T. warra sp. n. by their leg 2 prefemoral swellings. A female from Hastings Caves (in QVM 23:46570) has the posterior margin of the epigynum produced not as a low triangle with rounded apex, but as an oblong with rounded corners.

Figures

Figure 3. A, B Dorsal views of ring 12 metatergite of A Tasmaniosoma warra sp. n., paratype male QVM 23:46038, showing smooth surface, and B T. barbatulum sp. n., paratype male ex QVM 23:51512, showing three transverse rows of large, low, contiguous tubercles. C, D Ventral views of legpair 2 of C T. armatum Verhoeff, 1936, topotypical female ex QVM 23:46567, and D T. australe sp. n., paratype female ex QVM 23:46575, showing prefemoral swelling (s) and peg-like projection (p). Scale bars = 0.5 mm.

Figure 6. Tasmaniosoma armatum Verhoeff, 1936, topotypical male ex QVM 23:46567, legs 6 A and 7 B. T. australe sp. n., voucher male QVM 23:46573, left leg 6 lateral C and dorsal view D. T. bruniense sp. n., paratype male ex QVM 23:51633, left leg 6 E. T. alces sp. n., paratype male ex QVM 23:46762, legs 6 F and 7 G. Setation not shown; scale bar = 0.5 mm.

Figure 9. Tasmaniosoma australe sp. n., paratype males ex QVM 23:46575. A Posterior view of gonopod telopodites in situ B anterior and C medial views of right gonopod telopodite. Setation not shown in B and C; dashed lines mark course of prostatic groove. Scale bar = 0.2 mm.

Figure 24. A Localities as of 31 January 2010 for Tasmaniosoma alces sp. n. (filled triangles), T. aureorivum sp. n. (crosses), T. australe sp. n. (filled squares), T.bruniense sp. n. (stars), T. hesperium sp. n. (open circles), T. laccobium sp. n. (open triangle), T. maria sp. n. (filled circles) and T. warra sp. n. (open squares). See also Fig. 23. Scale bar = 50 km. (B) Map of Tasmania showing location of main map (rectangle).