Difference between revisions of "Austrarchaea westi"

Latest revision as of 12:29, 30 August 2012

Taxonavigation

Ordo: Araneae
Familia: Archaeidae
Genus: Austrarchaea

Name

Austrarchaea westi Rix & Harvey sp. n. – Wikispecies link – ZooBank link – Pensoft Profile

Vernacular name

Lamb Range Assassin Spider

Type material

Holotype male: Mount Williams, [Dinden National Park], 16°55'S, 145°40'E, pyrethrum, trees and logs, 1000 m, 2.XII.1993, G. Monteith, H. Janetzki (QMB S59537).
Other material examined. AUSTRALIA: Queensland: Dinden National Park: same data as holotype, 1 juvenile (QMB S59537).

Etymology

The specific epithet is a patronym in honour of Paul West, for his friendship to MSH over many years, and for helping fund the Western Australian Museum’s ‘archaeid project’ from 2009–2012.

Diagnosis

Austrarchaea westi can be distinguished from all other Archaeidae from north-eastern Queensland by the presence of a unique Type B pedipalp (Fig. 6), with very small bulb (width << 0.30 mm) (Figs 6, 12D), and by the relatively short embolus, which is distally enclosed within the conductor (Figs 6, 12D). This species can be further distinguished by the very short, barely differentiated accessory setae on the male chelicerae (Fig. 12B).

Description

Holotype male: Total length 3.13; leg I femur 3.23; F1/CL ratio 2.65. Cephalothorax reddish-brown; legs beige with darker annulations; abdomen mottled grey-brown and beige, with darker brown dorsal scute and sclerites (Fig. 12A). Carapace tall (CH/CL ratio 2.15); 1.22 long, 2.62 high, 1.13 wide, ‘neck’ 0.65 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) approaching posterior quarter of ‘head’ (ratio of HPC to post-ocular length 0.71), carapace gently sloping posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.27). Chelicerae with very short, barely differentiated accessory setae on anterior face of paturon (Fig. 12B). Abdomen 1.65 long, 1.10 wide; with two pairs of dorsal hump-like tubercles (HT 1-4); dorsal scute fused anteriorly to epigastric sclerites, extending posteriorly to first pair of hump-like tubercles; HT 3-4 each covered by separate dorsal sclerites. Unexpanded pedipalp (Figs 12C-E) of Type B morphology (Fig. 6), very small in size (width of bulb << 0.30), with large, retrolaterally directed, arched conductor; embolus curved, distally enclosed within conductor, without spur; tegular sclerite 3 (TS 3) porrect, spur-like, with pointed, pro-distally directed apex; TS 2-2a looped over retrolateral edge of conductor, TS 2 not strongly developed distally, TS 2a projecting beyond distal rim of conductor; TS 1 very small, obscured by TS 2-3, not visible in ventral view.
Female: Unknown.

Distribution and habitat

Austrarchaea westi is known only from Mount Williams, on the Lamb Range 11 km west of Cairns (Figs 21, 25). The two known specimens were collected in high altitude tropical rainforest.

Conservation status

Unknown (data deficient).

Original Description

• Rix, M; Harvey, M; 2012: Australian Assassins, Part III: A review of the Assassin Spiders (Araneae, Archaeidae) of tropical north-eastern Queensland ZooKeys, 218: 1-50. doi

Images

'Figure 6. Morphological differences between the five pedipalp types (Types A-E) identified for species of Austrarchaea from north-eastern Queensland, with left bulbs illustrated in ventral view at scale-identical sizes. Type A pedipalps are shared among at least five species from the Wet Tropics bioregion; Types B-E are autapomorphic for single species. Note especially the variation in the size and shape of the bulb, and the shape and orientation of the conductor. C = conductor; E = embolus; ESp = embolic spur; (TS)1-3 = tegular sclerites 1-3. Scale bar = 0.2 mm.  Figure 12. Austrarchaea westi sp. n. A–E, Holotype male (QMB S59537) from Mount Williams, Dinden National Park, NE. Queensland: A, cephalothorax and abdomen, lateral view; B, chelicerae, lateral view, showing lack of defined accessory setae; C–D, pedipalpal bulb, ventral view; E, detail of distal tegular sclerites, retrolateral view. C = conductor; E = embolus; T = tegulum; (TS)2-3 = tegular sclerites 2-3. Scale bars: A = 1.0 mm; D = 0.2 mm.  Figure 21. Distribution of Austrarchaea westi sp. n.: A, topographic map showing the known distribution of Archaeidae in the north-eastern Queensland Wet Tropics bioregion, with collection localities for Austrarchaea westi highlighted in yellow; B-C, topographic and satellite maps showing detail of inset (A). Labelled boundaries in (B) denote upland subregional zones of faunal endemism identified by Winter et al. (1984), Williams et al. (1996) and other authors for the central Wet Tropics (modified from Edward 2011). Small squares in (B–C) denote unidentified juvenile specimens; small circles denote unidentified female specimens; large circles denote described species of Austrarchaea. AU = Atherton Uplands; BK = Bellenden Ker/Bartle Frere; HI = Hinchinbrook Island; KU = Kirrama Uplands; LE = Lee Uplands; LU = Lamb Uplands; MT = Malbon-Thompson Uplands.  ' Figure 25. Summary distribution of the Austrarchaea daviesae species-group in tropical north-eastern Queensland, showing collections records for described species (labelled, with black circles) and unidentified juveniles or females (yellow circles) (see Table 1). Note the high proportion of unidentified specimens, especially within the Wet Tropics bioregion between Cooktown and Ingham.