Austrarchaea alani Kroombit Tops Assassin Spider Rix & Harvey

Rix, Michael G. & Harvey, Mark S., 2011, Australian Assassins, Part I: A review of the Assassin Spiders (Araneae, Archaeidae) of mid-eastern Australia, ZooKeys 123, pp. 1-100 : 24-26

Austrarchaea alani Kroombit Tops Assassin Spider Rix & Harvey sp. n. Figs 4A-E7A8A1836

Type material.

Holotype male: Kroombit Tops National Park, creek crossing off Tablelands Road, Queensland, Australia, 24°22'40"S, 150°59'46"E, sifting elevated leaf litter, subtropical rainforest with emergent eucalypts, 799 m, 26.X.2010, M. & A. Rix (QMB S90195).

Paratypes: Allotype female, same data as holotype (QMB S90194); 1 female, same data as holotype (QMB S90196); 2 females and 3 juveniles, same data as holotype (WAM T112550DNA: KT-63-F/KT-64-J/KT-65-J); 1 male and 2 juveniles, Kroombit Tops National Park, Rainforest Walk off Tablelands Road, near Munholme Creek, Queensland, Australia, 24°24'47"S, 151°02'22"E, sifting elevated leaf litter, subtropical rainforest, 753 m, 26.X.2010, M. & A. Rix (WAM T112551DNA: KT-66-M/KT-67-J).

Additional material (not examined).

AUSTRALIA: Queensland: Kroombit Tops National Park: Lower Dry Creek, pitfall trap, rainforest, 13-18.XII.1983, G. Monteith, V. Davies, J. Gallon, G. Thompson, 1♂ (QMB S30812); Three Moon Creek, rainforest, 9-19.XII.1983, V. Davies, J. Gallon, 2♀ (QMB S30816); Beauty Spot 98, rainforest, 9-19.XII.1983, V. Davies, J. Gallon, 1♀ (QMB S30803).

Etymology.

The specific epithet is a patronym in honour of Alan Rix, for his great assistance in helping to collect this species, and for a lifetime of generosity and support to the senior author.

Diagnosis.

Austrarchaea alani can be distinguished from all other Archaeidae from mid-eastern Australia except Austrarchaea aleenae by the very large, porrect tegular sclerite 3 (TS 3) (Figs 18D-F); and from Austrarchaea aleenae by the short comb of accessory setae on the male chelicerae (Fig. 18C).

This species can also be distinguished from other genotyped taxa from mid-eastern Australia (see Fig. 3B) by the following three unique nucleotide substitutions for COI and COII (n = 5): T(684), A(1218), C(1347).

Description.

Holotype male: Total length 2.69; leg I femur 2.83; F1/CL ratio 2.68. Cephalothorax reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige, with darker reddish-brown dorsal scute and sclerites (Fig. 18B). Carapace very tall (CH/CL ratio 2.28); 1.06 long, 2.41 high, 0.97 wide; ‘neck’ 0.49 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near posterior margin of ‘head’ (ratio of HPC to post-ocular length 0.85), carapace gently sloping anterior to HPC; ‘head’ moderately elevated postero-dorsally (post-ocular ratio 0.35) (Fig. 8A). Chelicerae with short comb of accessory setae on anterior face of paturon (Fig. 18C). Abdomen 1.38 long, 0.92 wide; with three pairs of dorsal hump-like tubercles (HT 1-6); dorsal scute fused anteriorly to epigastric sclerites, extending posteriorly to first pair of hump-like tubercles; HT 3-6 each covered by separate dorsal sclerites. Unexpanded pedipalp (Figs 18D-F) with broad, obliquely-angled foliate conductor; tegular sclerite 1 (TS 1) relatively short, almost triangular, obscured by conductor in retrolateral view; TS 2 thin, spiniform, longer than TS 1; TS 2a sinuous, largely obscured by TS 2; TS 3 very large, porrect, with broadly-pointed rectangular apex projecting well beyond retro-distal rim of tegulum.

Allotype female: Total length 3.41; leg I femur 3.06; F1/CL ratio 2.66. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige (Fig. 18A). Carapace very tall (CH/CL ratio 2.30); 1.15 long, 2.65 high, 1.04 wide; ‘neck’ 0.56 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near posterior margin of ‘head’ (ratio of HPC to post-ocular length 0.81), carapace sloping gently anterior to HPC; ‘head’ strongly elevated postero-dorsally (post-ocular ratio 0.38) (Fig. 7A). Chelicerae without accessory setae on anterior face of paturon. Abdomen 1.97 long, 1.38 wide; with three pairs of dorsal hump-like tubercles (HT 1-6). Internal genitalia with dense cluster of ≤ 15 variably shaped spermathecae on either side of gonopore, clusters meeting near midline of genital plate (Fig. 18G); innermost (anterior) spermathecae longest, sausage-shaped, curved antero-laterally; outermost (posterior) spermathecae bulbous; other spermathecae variably pyriform, straight, directed antero-laterally.

Variation: Males (n=2): total length 2.26-2.69; carapace length 1.03-1.06; carapace height 2.33-2.41; CH/CL ratio 2.28 (invariable). Females (n=4): total length 3.18-3.44; carapace length 1.15-1.18; carapace height 2.58-2.82; CH/CL ratio 2.23-2.39.

Distribution and habitat.

Austrarchaea alani is known only from rainforest habitats in the Kroombit Tops National Park of south-eastern Queensland (Fig. 36).

Conservation status. This species appears to be a short-range endemic taxon ( Harvey 2002b), which although potentially restricted in distribution, is abundant within the Kroombit Tops National Park (M. Rix, pers. obs.). It is not considered to be of conservation concern.