Prosopodesmus crater, Mesibov, Robert, 2012

Mesibov, Robert, 2012, New species of Prosopodesmus Silvestri, 1910 (Diplopoda, Polydesmida, Haplodesmidae) from Queensland, Australia, ZooKeys 190, pp. 33-54 : 35-39

Prosopodesmus crater sp. n. Figs 1A2A3A5A

Holotype.

Male, Eacham National Park, Qld, 17°18'S, 145°37'E [ ± 2 km], 760 m, 28 June 1971, R.W. Taylor and J. Feehan, berlesate 344, rainforest, ANIC 64-000213.

Paratypes.

1 male, 2 stadium 7 males, 2 stadium 7 females, 1 stadium 6 male, details as for holotype, ANIC 64-000212; 1 male, details as for holotype but 1-7 October 1972, R.W. Taylor, berlesate 428, ANIC 64-000214; 1 male, 2 females, Cathedral Fig, Qld, 17°10'52"S, 145°39'26"E [ ± 500 m], 720 m, 7 February 1996, G. Monteith, berlesate 907, rainforest, sieved litter, QM S37593; 1 male, 1 female, Downey Creek, 25 km SE of Millaa Millaa, Qld, 17°40'48"S, 145°46'58"E [ ± 500 m], 400 m, 7 December 1988, G. Monteith and G. Thompson, berlesate 813, rainforest, sieved litter, QM S91625.

Other material. 1 male, Cammoo Caves near Rockhampton, Qld, 23°10'S, 150°28'E [ ± 2 km], 25 October 1976, R.W. Taylor and T.A. Weir, berlesate 535, dense, low, closed forest, ANIC 64-000215.

Diagnosis.

Males and females with head + 20 rings; adults 7-8 mm long; midbody metatergites typically with 3 transverse rows of 10 large tubercles; posterior por tion of prozonite with small disks, no microtubercles; ozopores not on porosteles; gonopod telopodite with single posteriad bend, near tip.

Description.

Male with head + 20 rings, ca 7 mm long. Colour in alcohol pale yellow; lightly encrusted with fine soil particles. Ring 12 with maximum vertical diameter 0.7 mm; maximum width (including paranota) 0.9 mm and 1.6X prozonite width; paranotal length ca 1/2 of total ring length.

Head (Fig. 1A) facing ground, covered by anterior collum edge in dorsal view; vertex microtuberculate; frons with large, irregular tubercles with microvillose texture; clypeus smooth, sparsely setose ventrally. Antennal sockets separated by slightly more than a socket diameter. Retracted antennae with distalmost antennomeres held in groove formed by lateral edge of frons anteriorly and confluent lateral collum and ring 2 tergite edges posteriorly. Antennomere relative widths (5,6)>(2,3,4), relative lengths 6>5>(2,3,4).

Collum with 12 lobes along anterior edge (Fig. 1A). Collum, ring 2 tergite and metatergites 5-15 about equally wide; rings 3,4 slightly narrower; rings16-18 progressively narrowing. Collum, tergites and metatergites textured with large, low tubercles, each with irregular, roughened, microvillose fine structure; 3 transverse rows of typically 10+10+10 tubercles on midbody metatergites. Dorsal and lateral setae on collum, tergites and metatergites sparse, bisegmented, the distal portion flattened, slightly flared at tip and minutely toothed along distal edge. Anterior portion of prozonite (Fig. 2A) cellular, posterior portion irregularly covered with small, more or less round, variably sized, convex disks. Limbus a smooth, straight-edged lamella.

Ring 2 tergite edge lower than collum edge and ring 3 tergite edge. Paranota set low on body and declined at about 45°, subquadrate in dorsal view; lateral margin notched into 3 lobes at ca 1/8 and 1/2 the paranotal length.

Ozopore not on porostele, inconspicuous near posterolateral corner of paranotum; pore formula 5, 7, 9, 10, 12, 13, 15-19.

Sternites as wide as long. Legs short, hidden by paranota in dorsal view. Relative podomere lengths (femur, tarsus)>prefemur>(postfemur, tibia).

Spiracles not evident.

Telson (as for Prosopodesmus monteithi sp. n in Fig. 1B) facing ground; preanal ring with 5 lobes on each side and 1 larger lobe (epiproct) apically. Spinnerets recessed in individual chambers, basal sheaths with unnotched distal edges; setal shafts smooth. Paraprocts more or less flat, rounded-rectangular; paraproctal setae close to and equidistant from margin. Hypoproct trapezoidal, hypoproctal setae not on raised tubercles.

Gonopore inconspicuous on leg 2 coxa. Ring 6 metatergite with slight medial excavation on posterior margin ventrally, accommodating tips of retracted gonopod telopodites. Aperture ovoid, as wide as ring 7 prozonite and extending anteriorly to occupy ventral portion of prozonite. Gonocoxae (Fig. 3A) massive, slightly tapering posteroventrally, surface densely microtuberculate; flat ventrally with a few setae near medial side; medial side slightly concave.

Telopodite base in shallow recess at posteroventral corner of gonocoxa. Telopodites (Figs 3A, 5A) slender, straight, more or less uniformly wide, parallel, just touching when retracted, slightly convex anteriorly, slightly concave ventrally; bent posteriorly at tip; with thin, rounded tabs projecting posteriorly from lateral edge at between 1/4 and 1/2 the telopodite length and just basal to the apical bend; with thin, rounded tab similarly extending the medial edge just distal to the bend. Telopodites with a few larger setae to about 1/2 telopodite length on posterior surface laterally; with numerous fine setae around and just inside basal concavity into which the prominent cannula inserts. Prostatic groove running straight to small, low mound on middle of posterior telopodite surface at about 3/4 telopodite length; mound covered with ‘hairpad’ of slender, pointed villi.

Female with head + 20 rings; a little larger than male, ca 8 mm long. Epigyne ca 1/3 ring width, slightly raised, rounded rectangular with straight distal edge; cyphopods not examined.

Distribution.

Rainforest on the Atherton Tableland southwest from Cairns, Queensland, with a known north-south range of ca 40 km (Fig. 8). There is also one questionable record from the Cammoo Caves area in central coastal Queensland. (See Remarks.)

Etymology.

Latin crater, ‘cup’. The type locality surrounds Lake Eacham, a crater lake on the Atherton Tableland in far north Queensland.

Remarks.

The male in 'Other material’ is from a site nearly 800 km south and east from the nearest other Prosopodesmus crater locality. This specimen is from the same ANIC berlesate that indicated a similar 800+ km disjunction in the range of the unrelated millipede Asphalidesmus magnus Mesibov, 2011 ( Mesibov 2011). Although the Cammoo Caves Prosopodesmus crater is very slightly different in gonopod details from those collected on the Atherton Tableland, the most likely explanation is that the Cammoo Caves specimens of Prosopodesmus crater and Asphalidesmus magnus were actually collected in the Wet Tropics, and that the locality labels are incorrect.