Difference between revisions of "Austrarchaea hoskini"

Latest revision as of 12:29, 30 August 2012

Taxonavigation

Ordo: Araneae
Familia: Archaeidae
Genus: Austrarchaea

Name

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

• Austrarchaea sp. n. Rix and Harvey 2012b^[1]: 376, fig. 1G.

Vernacular name

Mount Elliot Assassin Spider

Type material

Holotype male: Mount Elliot, [Bowling Green Bay National Park], Upper North Creek, Queensland, Australia, [19°29'S, 146°57'E], rainforest, 1000 m, 2–5.XII.1986, G. Monteith, G. Thompson, S. Hamlet (QMB S30811).

Paratypes

Allotype female, Mount Elliot, [Bowling Green Bay National Park], North Creek, Queensland, Australia, 19°29'S, 146°57'E, 1000 m, 25–27.III.1991, G. Monteith, D. Cook (QMB S17937); 1 male, 1 female, same data (QMB S23045).

Other material examined

AUSTRALIA: Queensland: Bowling Green Bay National Park: same data as holotype, 1 juvenile (QMB S30811); same data as holotype except pitfall trap, 3–5.XII.1986, 1 juvenile (QMB S30839).

Etymology

The specific epithet is a patronym in honour of Dr Conrad Hoskin, for his contributions to our understanding of Wet Tropics biogeography, and for his efforts in documenting the remarkable endemic biota of Mount Elliot.

Diagnosis

Austrarchaea hoskini can be distinguished from all other Archaeidae from north-eastern Queensland by the presence of a unique Type D pedipalp (Fig. 6), with a prolaterally directed conductor (Figs 6, 14E), very large, dagger-shaped tegular sclerite 3 (TS 3) (Figs 6, 14E–F), and prominent, rounded, fin-shaped embolic spur (Fig. 14E).

Description

Holotype male: Total length 3.44; leg I femur 3.59; F1/CL ratio 2.86. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige, with darker brown dorsal scute and sclerites (Fig. 14B). Carapace very tall (CH/CL ratio 2.29); 1.26 long, 2.87 high, 1.21 wide, ‘neck’ 0.59 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near posterior third of ‘head’ (ratio of HPC to post-ocular length 0.63), carapace almost horizontal posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.28). Chelicerae with short brush of accessory setae on anterior face of paturon (Fig. 14C). Abdomen 2.00 long, 1.54 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 14D–F) of Type D morphology (Fig. 6), with large, prolaterally directed, arched conductor; embolus distally directed, sinuous, with prominent, rounded, fin-shaped spur proximal to distal kink in embolus, embolus projecting beyond distal rim of conductor by ~1/3 length of exposed embolic portion; tegular sclerite 3 (TS 3) very large, dagger-like, directed pro-ventrally across bulb; TS 2-2a forming looped, figure-of-eight-shaped structure in ventral view, TS 2 rounded distally, TS 2a projecting beyond distal rim of conductor to near tip of embolus; TS 1 very small, indistinct, probably embedded within haematodochal membranes.
Allotype female: Total length 3.79; leg I femur 3.44; F1/CL ratio 2.44. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige (Fig. 14A). Carapace tall (CH/CL ratio 2.10); 1.41 long, 2.96 high, 1.31 wide; ‘neck’ 0.72 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 almost horizontal anterior and slightly posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.29). Chelicerae without accessory setae on anterior face of paturon. Abdomen 2.31 long, 1.87 wide; with four pairs of dorsal hump-like tubercles (HT 1-4). Internal genitalia (Fig. 14G) with cluster of ~6 variably-shaped spermathecae on either side of gonopore, clusters widely separated along midline of genital plate; innermost (anterior) spermathecae longest, sausage-shaped, bent laterally; other spermathecae variably sausage-shaped or pyriform.
Variation: Males (n = 2): total length 3.38–3.44; carapace length 1.22–1.26; carapace height 2.78–2.87; CH/CL ratio 2.28–2.29. Females (n = 2): total length 3.59–3.79; carapace length 1.41 (invariable); carapace height 2.96–3.12; CH/CL ratio 2.10–2.21.

Distribution and habitat

Austrarchaea hoskini is known only from Mount Elliot, 30 km south-east of Townsville (Figs 23, 25). The few known specimens were collected in high altitude rainforest along North Creek.

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

Other References

1. ↑ Rix M, Harvey M (2012b) Phylogeny and historical biogeography of ancient assassin spiders (Araneae: Archaeidae) in the Australian mesic zone: evidence for Miocene speciation within Tertiary refugia. Molecular Phylogenetics and Evolution 62: 375-396. doi: 10.1016/j.ympev.2011.10.009

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 14. Austrarchaea hoskini sp. n. A–B, Cephalothorax and abdomen, lateral view: A, allotype female (QMB S17937) from Mount Elliot, Bowling Green Bay National Park, NE. Queensland; B, holotype male (QMB S30811) from Mount Elliot, Bowling Green Bay National Park, NE. Queensland. C, Holotype male chelicerae, lateral view, showing accessory setae. D–F, Holotype male pedipalp: D–E, bulb, ventral view; F, detail of distal tegular sclerites, retrolateral view. G, Allotype female internal genitalia, postero-ventral view (as seen through posterior rim of genital plate). C = conductor; E = embolus; ESp = embolic spur; GP = genital plate; T = tegulum; (TS)2-3 = tegular sclerites 2-3. Scale bars: A-B = 1.0 mm; E = 0.2 mm.  Figure 23. Distribution of Austrarchaea hoskini sp. n.: A, topographic map showing the known distribution of Archaeidae in the north-eastern Queensland Wet Tropics bioregion, with collection localities for Austrarchaea hoskini 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 southern Wet Tropics (modified from Edward 2011). EU = Elliot Uplands; HU = Halifax 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.