Tasmaniosoma nicolaus, Mesibov, Robert, 2015

Mesibov, Robert, 2015, Three new species of Tasmaniosoma Verhoeff, 1936 (Diplopoda, Polydesmida, Dalodesmidae) from northeast Tasmania, Australia, ZooKeys 488, pp. 31-46: 40-43

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scientific name

Tasmaniosoma nicolaus

sp. n.

Taxon classification Animalia Polydesmida Dalodesmidae

Tasmaniosoma nicolaus   sp. n. Figs 1C, F, 2C, 8, 9A


Male, Catos Road, Tas, -41.5350 148.0842 ± 50 m (GPS), 520 m a.s.l., 9 February 2015, R. Mesibov, QVM 23:53864 (ex QVM 23:53860).


18 males, details as for holotype, QVM 23:53860.

Other material.

5 males and 3 females (see Suppl. material 1 for details).


Member of the " anubis   group" within Tasmaniosoma   (see Discussion); distinguished from Tasmaniosoma anubis   sp. n., Tasmaniosoma barbatulum   and Tasmaniosoma fragile   by the absence of a basally directed cluster of stout, rod-like setae on the posterior surface of the gonopod telopodite; from Tasmaniosoma clarksonorum   , Tasmaniosoma compitale   and Tasmaniosoma hickmanorum   by the absence of a lateral process on the telopodite apex; and from Tasmaniosoma fasciculum   by the telopodite apex extending as a mediolaterally flattened process in the shape of a bird’s head pointed posteriorly.


Male/female approximate measurements: length 11/10 mm, midbody paranota width 1.3/1.2 mm, maximum vertical diameter 1.0/1.0 mm. Live and freshly preserved adults (Figs 1C, F, 9A) with dark reddish brown head and antennae; body with yellowish ground colour, dark reddish brown on paranotal margins, dorsolaterally on prozonites, as cellular borders in patches laterally, and as diffuse streaks and cellular borders dorsomedially and as margin lines posteriorly on pro- and metazonites; legs darkening slightly distally. Long-preserved animals almost entirely decoloured.

Non-gonopodal features in males as for Tasmaniosoma anubis   sp. n., but overall ring widths 6>5>(4,head)>(3,2)>collum; prefemoral swellings to about leg 20. Legs 6 and 7 bases (Fig. 2C) well- and equally separated; no sternal tab by leg 6; tall, rounded sternal tab by leg 7 with medial brush of thick, rod-like, pointed setae; leg 7 coxa without distomedial bulge.

Telopodites (Fig. 8) almost straight, parallel; extending nearly to leg 6 bases when retracted; without prominent posterobasal shelves. Telopodite straight, subcylindrical, at about 3/4 telopodite height swelling distolaterally, centrally and medially projecting as large anteroposteriorly flattened process with apex twisted to be mediolaterally flattened, shaped like bird’s head and pointed posteriorly; smaller sickle-shaped process arising at base of apex and directed posterodistally; and medial margin of large process curving posteriorly as thin tab with rounded margin. Solenomere short, slightly helicoid, pointed, arising posterior to base of large process and directed distally. Sparse, fine, fairly long setae on lateral and posterolateral surfaces to about 1/2 telopodite height. Two closely packed clusters of stout, rod-like, pointed setae: one (ca 12 setae) on anterolateral surface near base of large telopodite process and directed distally and slightly anteriorly, the other (ca 15 setae) arising posteromedially just posterior to solenomere base and directed distally and slightly posteriorly. Prostatic groove running more or less straight to base of solenomere on medial surface.

Female with legs more slender and prefemora and femora not swollen. Epigynum ca 1/3 width of ring 2, posterior margin produced medially as small, rounded triangle with irregular margin. Cyphopods not examined. (See also Remarks, below.)


Eucalypt forest over <40 km2 on the Nicholas Range and the Mt Elephant area at the eastern end of the Fingal Valley in northeast Tasmania, on both north- and south-facing slopes at ca 300-500 m a.s.l. (Figs 5A, 7B). Co-occurs with Tasmaniosoma barbatulum   , Tasmaniosoma interfluminum   sp. n. and Tasmaniosoma orientale   in bark and leaf litter.


Latinised “Nicholas” for the Nicholas Range, type locality of this species; noun in apposition.


All of the known Tasmaniosoma nicolaus   sp. n. collection sites are in forest patches with evidence of past logging and burning, and part of the known range of Tasmaniosoma nicolaus   sp. n. is within the ca 800 ha Nicholas Range Regional Reserve. Like Tasmaniosoma anubis   sp. n., Tasmaniosoma nicolaus   sp. n. can be locally abundant: I found most of the 19 type specimens in bark litter under two Eucalyptus   trees.

My identification of three females as Tasmaniosoma nicolaus   sp. n. (QVM 23:53635) is tentative. Two of the three females are missing legs 2.