Austrarchaea platnickorum New England 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 : 28

Austrarchaea platnickorum New England Assassin Spider Rix & Harvey sp. n. Figs 7J9C2139

Type material.

Holotype male: New England National Park, Banksia Point, Beech Forest and start of Lyrebird Track, New South Wales, Australia, 30°29'29"S, 152°24'22"E, sifting elevated leaf litter under tussocky snow grass, Nothofagus rainforest and adjacent snow gum woodland, 1491 m, 18.IV.2010, M. Rix, D. Harms (AMS KS114971).

Paratypes: Allotype female, same data as holotype (AMS KS114970); 3 males, 2 females and 5 juveniles, same data as holotype (WAM T112558DNA: Ar51-101-M/Ar51-102-F/Ar51-103-J).

Other material examined.

AUSTRALIA: New South Wales: New England National Park: Banksia Point, ex pan traps, 2-15.X.1984, I. Naumann, J. Cardale, 1 juvenile (ANIC); Point Lookout, 22.III.1980 - 16.III.1981, G. Monteith, 1 juvenile (QMB S30819).

Etymology.

The specific epithet is a patronym in honour of Dr Norman Platnick and his wife Nancy. Dr Platnick’s pioneering research into many different spider lineages - including Archaeidae - has inspired a generation of arachnologists.

Diagnosis.

Austrarchaea platnickorum can be distinguished from all other Archaeidae from mid-eastern Australia by the very long, spiniform tegular sclerite 1 (TS 1) (Fig. 21F) combined with the unique shape of the conductor (Figs 21D-E), which is thin and ‘arrow-shaped’, with a long triangular apex.

This species can also be distinguished from other genotyped taxa from mid-eastern Australia (see Fig. 3B) by the following eight unique nucleotide substitutions for COI and COII (n = 3): A(354), A(573), A(624), T(986), G(1061), G(1077), C(1110), T(1533).

Description.

Holotype male: Total length 3.28; leg I femur 2.67; F1/CL ratio 2.31. 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. 21B). Carapace tall (CH/CL ratio 2.07); 1.15 long, 2.38 high, 1.08 wide; ‘neck’ 0.59 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near middle of ‘head’ (ratio of HPC to post-ocular length 0.59), carapace gently sloping posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.26) (Fig. 9C). Chelicerae with brush of accessory setae on anterior face of paturon (Fig. 21C). Abdomen 1.85 long, 1.41 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 21D-F) with thin, triangular ‘arrow-shaped’ conductor; tegular sclerite 1 (TS 1) very long, spiniform, visible in retrolateral view (TS 1 broken, rod-like on left pedipalp; Fig. 21F); TS 2 spur-like, poorly-sclerotised, longer than TS 1; TS 2a sinuous, largely obscured by TS 2; TS 3 indistinct, embedded within distal haematodocha, barely visible beyond retro-distal rim of tegulum.

Allotype female: Total length 4.31; leg I femur 2.79; F1/CL ratio 2.14. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige (Fig. 21A). Carapace tall (CH/CL ratio 2.04); 1.31 long, 2.67 high, 1.21 wide; ‘neck’ 0.69 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’ not strongly elevated dorsally (post-ocular ratio 0.27) (Fig. 7J). Chelicerae without accessory setae on anterior face of paturon. Abdomen 2.72 long, 1.95 wide; with three pairs of dorsal hump-like tubercles (HT 1-6). Internal genitalia with dense cluster of ≤ 20 variably shaped spermathecae on either side of gonopore, clusters meeting near midline of genital plate (Fig. 21G); innermost (anterior) spermathecae longest, sausage-shaped, curved antero-laterally; other spermathecae variably aciniform, mostly straight, directed antero-laterally.

Variation: Males (n=4): total length 2.97-3.28; carapace length 1.10-1.15; carapace height 2.21-2.38; CH/CL ratio 2.00-2.07. Females (n=3): total length 3.79-4.62; carapace length 1.26-1.31; carapace height 2.54-2.67; CH/CL ratio 2.02-2.12. The holotype male and an additional paratype male (WAM T112558) of this species have a shorter, partially broken tegular sclerite 1 (TS 1) on each left pedipalp (Fig. 21F).

Distribution and habitat.

Austrarchaea platnickorum is known only from rainforest and mesic closed forest habitats in the New England National Park of north-eastern New South Wales (Fig. 39).

Conservation status.

This species has an imperfectly known distribution, and although potentially restricted, appears to be abundant within the World Heritage-listed New England National Park near Point Lookout (M. Rix, pers. obs.). It is not considered to be of conservation concern.