Austrarchaea hoskini Rix & Harvey

Rix, Michael G. & Harvey, Mark S., 2012, Australian Assassins, Part III: A review of the Assassin Spiders (Araneae, Archaeidae) of tropical north-eastern Queensland, ZooKeys 218, pp. 1-50 : 15-17

Austrarchaea hoskini Rix & Harvey sp. n. Figs 142325

Austrarchaea sp. n. Rix and Harvey 2012b: 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, 14 E–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 14 D–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 separat ed 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).