Austrarchaea dianneae Rix & Harvey 2011

Austrarchaea dianneae is a species of spider in the family Archaeidae. It is endemic to Australia.

Holotype male: Total length 3.03; leg I femur 3.12; F1/CL ratio 2.83. 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. 11B). Carapace very tall (CH/CL ratio 2.37); 1.10 long, 2.62 high, 1.02 wide; ‘neck’ 0.51 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 0.87), carapace gently sloping and almost horizontal anterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.29) (Fig. 8H). Chelicerae with brush of accessory setae on anterior face of paturon (Fig. 11C). Abdomen 1.69 long, 1.33 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 11D-F) with broad, foliate conductor, curved laterally with triangular apex; tegular sclerite 1 (TS 1) spiniform, obscured by conductor in retrolateral view; TS 2 spur-like, longer than TS 1; TS 2a sinuous, largely obscured by TS 2; TS 3 embedded proximally within distal haematodocha, with sharply-pointed, triangular apex projecting beyond retro-distal rim of tegulum. Allotype female: Total length 3.74; leg I femur 3.18; F1/CL ratio 2.43. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige, palest posteriorly (Fig. 11A). Carapace very tall (CH/CL ratio 2.28); 1.31 long, 2.97 high, 1.21 wide; ‘neck’ 0.65 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near middle of ‘head’ (ratio of HPC to post-ocular length 0.55), carapace gently sloping posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.25) (Fig. 7H). Chelicerae without accessory setae on anterior face of paturon. Abdomen 2.15 long, 1.64 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. 11G); innermost (anterior) spermathecae longest, sausage-shaped, curved antero-laterally; other spermathecae variably pyriform, curved, directed laterally. Variation: Males (n=5): total length 2.73–3.21; carapace length 1.09–1.13; carapace height 2.53–2.62; CH/CL ratio 2.24–2.39. Females (n=2): total length 3.64–3.74; carapace length 1.31 (invariable); carapace height 2.87–2.97; CH/CL ratio 2.20–2.28.

Austrarchaea dianneae is known only from subtropical rainforest habitats in the Tamborine and Lamington National Parks south of Brisbane, south-eastern Queensland (Fig. 29). At Binna Burra (Lamington National Park) it has been found in sympatry with Austrarchaea nodosa, in the only known example of two-species sympatry among Australian archaeids (see Nomenclatural Remarks for Austrarchaea nodosa, above).