Austrarchaea mcguiganae Southern Highlands 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 : 37-39

Austrarchaea mcguiganae Southern Highlands Assassin Spider Rix & Harvey sp. n. Figs 7O9H2745

Type material.

Holotype male: Monga National Park, Link Road, New South Wales, Australia, 35°34'04"S, 149°54'14"E, 16.III.1999, L. Wilkie, R. Harris, H. Smith (AMS KS62790).

Paratypes: Allotype female, Monga National Park, off Link Road, New South Wales, Australia, 35°34'03"S, 149°54'15"E, sifting elevated leaf litter, complex eucalypt forest with thick understory near tree fern gully, 864 m, 6.IV.2010, M. Rix, D. Harms (AMS KS114975); 1 female and 5 juveniles, same data (WAM T112567DNA: Ar28-47-J/Ar28-128-J).

Additional material examined (of tentative identification).

AUSTRALIA: New South Wales: Deua National Park: Coondella Fire Trail, 35°58'44"S, 149°53'05"E, 11.III.1999, J. Tarnawski, S. Lassau, 1♀ (AMS KS62791). Badja State Forest: Badja Fire Trail, 36°07'30"S, 149°31'37"E, 13.III.1999, J. Tarnawski, S. Lassau, 1 juvenile (AMS KS62792); off Peters Road, near junction with Badja Forest Road, 36°07'38"S, 149°31'36"E, sifting elevated leaf litter, complex eucalypt forest with thick understory, 1075 m, 5.IV.2010, M. Rix, D. Harms, 14 juveniles (WAM T112577DNA: Ar27-129-J/Ar27-130-J/Ar27-131-J).

Etymology.

The specific epithet is a patronym in honour of the late Margaret McGuigan (1920-2010), for her love of the Southern Highlands, and for a lifetime of kindness and support to the senior author.

Diagnosis.

Austrarchaea mcguiganae can be distinguished from all other Archaeidae from mid-eastern Australia by the relatively short, rod-like, proximally-widened tegular sclerite 1 (TS 1) (Figs 27D-E) combined with the long brush of accessory setae on the male chelicerae (Fig. 27C).

This species can also be distinguished from other genotyped taxa from mid-eastern Australia (see Fig. 3B) by the following seven unique nucleotide substitutions for COI and COII (n = 2): T(57), C(144), T(156), G(465), G(504), C(798), G(1548).

Description.

Holotype male: Total length 3.17; leg I femur 2.81; F1/CL ratio 2.49. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige, with darker reddish-brown dorsal scute and sclerites (Fig. 27B). Carapace tall (CH/CL ratio 2.00); 1.13 long, 2.26 high, 1.06 wide; ‘neck’ 0.54 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 gently sloping posterior to HPC; ‘head’ moderately elevated postero-dorsally (post-ocular ratio 0.32) (Fig. 9H). Chelicerae with long brush of accessory setae on anterior face of paturon (Fig. 27C). Abdomen 1.64 long, 1.10 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. Fully expanded pedipalp (Figs 27D-E) with conductor hinged to, and obscured by, embolic haematodocha; tegular sclerite 1 (TS 1) rod-like, bluntly-pointed, visible in retro-ventral view; TS 2 spur-like, slightly longer than TS 1, largely obscured by TS 3; TS 2a sinuous, filiform, exposed distally; TS 3 exposed, plate-like, overlying TS 2, with curved, triangular apex directed toward proximal conductor.

Allotype female: Total length 3.49; leg I femur 2.86; F1/CL ratio 2.28. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige (Fig. 27A). Carapace tall (CH/CL ratio 2.04); 1.26 long, 2.56 high, 1.18 wide; ‘neck’ 0.64 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near middle of ‘head’ (ratio of HPC to post-ocular length 0.60), carapace gently sloping posterior to HPC; ‘head’ moderately elevated dorsally (post-ocular ratio 0.33) (Fig. 7O). Chelicerae without accessory setae on anterior face of paturon. Abdomen 2.00 long, 1.41 wide; with three pairs of dorsal hump-like tubercles (HT 1-6). Internal genitalia with cluster of ≤ 12 variably shaped spermathecae on either side of gonopore, clusters meeting near midline of genital plate (Fig. 27F); innermost (anterior) spermathecae longest, sausage-shaped, curved antero-laterally; other spermathecae variably aciniform, straight, directed antero-laterally.

Variation: Females (n=2): total length 3.38-3.49; carapace length 1.26 (invariable); carapace height 2.56-2.62; CH/CL ratio 2.04-2.08.

Distribution and habitat.

Austrarchaea mcguiganae is known only from mesic closed forest habitats in the Monga National Park of southern New South Wales (Fig. 45). A female specimen from Deua National Park may also belong to this species based on proximity, and numerous juvenile specimens from the Badja State Forest possess divergent mtDNA sequences indicative of possible speciation (Fig. 3B).

Conservation status.

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