Cavisternum attenboroughi sp. nov. Baehr & Raven Figs. 3–19

Types: AUSTRALIA: Northern Territory: Male holotype from Fish River Station, F 26, Heath woodland on sandstone, litter, 14.04750°S, 130.76638 °E, 22 Apr.–03 May 2012, (R. Whyte), deposited in QM (QM S91149 PBI_OON 23638). Female allotype collected with holotype, deposited in QM (QM S91150 PBI_OON 23639).

Other specimens examined: AUSTRALIA: same data as holotype, 1Ƥ (QM S91151, PBI_OON 23640); Fish River STN B5a, vine thicket and eucalypt among boulders, litter, -14.07388°, 130.78583°, 22 Apr.–03 May 2012, R. Raven, 13 (QM S91152, PBI_OON 23646 SEM).

Etymology: The specific name is a patronym honouring the work of media presenter and naturalist Sir David Attenborough because of his contributions in recognizing the magnificence of the world’s biodiversity and his support for life on planet earth.

Diagnosis. The male of C. attenboroughi resembles C. bertmaini Baehr et al. 2010 with the sternal concavity occupying about half the sternal length and having a pear-shaped cymbium-bulb complex. It can be distinguished by a more oval sternal field of clavate setae and its palpal tip bearing a long, bifurcate embolus with two prolaterally curved folds. The female can be separated from C. bertmaini by its semicircular epigastric area, with dark circular copulatory opening in the region of the abdomen between anterior and posterior spiracles.

MALE: (PBI_OON 23638, Figs. 3–13): Total length 1.01.Prosoma, mouthparts, and abdominal scuta pale orange, carapace slightly elevated in lateral view, surface smooth; lateral margin without denticles. Eyes: ALE 0.043; PME 0.037; PLE 0.040; ALE largest and circular, PME oval, PLE circular; posterior eye row straight from above and front; ALE separated by less than their radius, ALE-PLE touching, PME touching throughout most of their length, PLE-PME touching. Sternum longer than wide, fused to carapace, with small oval median depression covered laterally with clavate setae (Fig. 4); without radial furrows between coxae I–II, II–III, III–IV, surface smooth. Chelicerae slightly divergent, anterior face unmodified, fang tip long triangular, bent backwards (Fig. 8). Labium triangular, fused to sternum, anterior margin indented at middle. Endites distally not excavated, serrula present in single row, anteromedian tip with one strong, tooth-like projection. Abdomen ovoid, rounded posteriorly. Book lung covers large, ovoid. Pedicel tube short, scuto-pedicel region unmodified, scutum not extending far dorsal of pedicel. Dorsal scutum weakly sclerotized, covering full length of abdomen, no soft tissue visible from above, surface smooth. Epigastric scutum weakly sclerotized, strongly protruding (Fig. 9). Postepigastric scutum weakly sclerotized, long, almost rectangular, covering nearly full length of abdominal length, fused to epigastric scutum, anterior margin unmodified, with short posteriorly directed lateral apodemes (Fig. 5). Spinneret scutum present, incomplete ring. Colulus represented only by setae. Legs yellow, patella plus tibia I shorter than carapace. Leg spines absent. Tarsi I to IV without inferior claw. Epigastric region with sperm pore small, oval, situated in front of anterior spiracles, with strongly protruding extension (Fig. 9). Palpal cymbium (Figs 10–13) completely fused with bulb, no seam visible, dorsally covered with plumose setae, pear-shaped, tip bearing a long, bifurcate embolus with two prolaterally curved folds and a small club-shaped basal process.

FEMALE (PBI_OON 23639, Figs. 14–19): Total length 1.04. As in male except as noted. ALE: 0.041; PME: 0.035; PLE: 0.039. Chelicerae normal (Figs 15, 17). Endites anteromedian tip unmodified. Female palpal claw absent. Sternum without concavity (Fig. 15). Abdomen postepigastric scutum not fused to epigastric scutum (Fig. 16). Epigastric area semicircular, with dark circular copulatory opening at level between anterior and posterior spiracles.