Austrarchaea mcguiganae Rix & Harvey 2011

Austrarchaea mcguiganae is a species of spider in the family Archaeidae. It is endemic to Monga National Park in New South Wales, Australia.

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.

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).