Tasmaniosoma aureorivum, 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 : 42-44

Tasmaniosoma aureorivum sp. n.

urn:lsid:zoobank.org:act:CFA149D3-3B8C-4425-A626-E3FC5BACC621

Fig. 8 ; map Fig. 24

Holotype. Male, Australia, Tasmania, Gold Creek , 42°47'41"S 146°35'04"E ( DN 659617) ± 100 m, 570 m, 24 February 1994, R. Mesibov, QVM 23 :46599.

Paratypes. 3 males, 3 females, Growling Swallet , Junee-Florentine karst, Tas, 42°41’S 146°30’E ( DN 590735) ± 1 km, 26 March 1989, S. Eberhard, Glowworm Chamber, field no. JF36-10, QVM 23 :12120 ; 1 male, Ray Benders Cave , Risbys Basin , Junee-Florentine karst, Tas, 42°46'11"S 146°36'15"E ( DN 675645) ± 1 km, 10 June 1992, S. Eberhard, QVM 23 :12972 .

Other material. None known.

Diagnosis. Metatergites without tubercles, gonopod telopodite with large, laterally directed, rod-like, pointed process.

Description. Male/female approximate measurements: length 13/ 12 mm, ring 12 paranota width 1.3/ 1.3 mm. Live colour not known; in alcohol, completely decoloured.

Most non-gonopod details as for T. armatum , but antennomere 3 longest, ring 12 paranota 1.3 × as wide as prozonite, leg 6 tarsus 1.5 × as long as femur. Ring 6 sternite with legs 6 closer together than legs 7; legs 6 and 7 tabs long with sparse fine setae (not in discrete brushes); no setae on anterior margin of sternite.

Gonopod telopodites straight, tapering distally; base extended posterolaterally as distally concave shelf; posterior surface with thickened longitudinal ridge to ca 1/2 telopodite height. Telopodite apex with four processes: (a) pointed, rod-like process arising on anterior surface and directed distally; (b) large, rod-like, pointed process arising on posterior surface, bent at base and directed laterally; (c) laminate process arising apically and curving posteriorly, the tip sometimes notched; (d) small solenomere arising posteromedially and directed posterodistally. Apex produced as small, rounded knob between solenomere and laminate process. Basal shelf concavity with long, fine setae; row of short, stout setae on posteromedial surface to ca 3/4 telopodite height, increasing in length and thickness distally. Prostatic groove on medial surface of telopodite, curving gradually to solenomere base.

Female with sternites as wide as long; posterior margin of epigynum produced as short trapezoid.

Distribution. Known from three sites in eucalypt forest (holotype) and caves (paratypes) near Maydena in south central Tasmania, with a maximum distance between sites of ca 15 km ( Fig. 24 ).

Etymology. Latin aureus, “golden”, + rivus, “stream”, noun used as adjective, after the type locality, Gold Creek.

Remarks. Telopodite details vary a little among the five known males. In the holotype the process arising on the anterior surface is longer than in the paratype illustrated and reaches almost as far distally as the top of the laminate process, which has a small tooth on the concave, posterior edge.

The paratypes are not troglomorphic and are likely to be from accidentally cavedwelling populations. Th e holotype is from a non-karst site in the Styx River catchment. I have unsuccessfully searched for this species in forest in the adjoining Tyenna River catchment, where it may be rare.

Figures

Figure 8. Tasmaniosoma aureorivum sp. n., paratype male ex QVM 23:12120. Posterior A, lateral B and anterior C views of left gonopod telopodite. Scale bar = 0.2 mm; dashed line marks course of prostatic groove.

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).