Eriauchenius lukemacaulayi, Wood, Hannah M. & Scharff, Nikolaj, 2017

Wood, Hannah M. & Scharff, Nikolaj, 2017, A review of the Madagascan pelican spiders of the genera Eriauchenius O. Pickard-Cambridge, 1881 and Madagascarchaea gen. n. (Araneae, Archaeidae), ZooKeys 727, pp. 1-96 : 1

Eriauchenius lukemacaulayi sp. n. Figs 14, 32

Type material.

Male holotype: Madagascar, Fianarantsoa, Parc National Andrigitra, 34 km S Ambalavao, 22°09'24.9"S, 46°57'08.7"E, 1830 m, 8-9 Jan 2009, primary montane rainforest, general collecting day, beating vegetation, H. Wood (deposited in USNM: USNMENT01377191).

Other material examined.

Female paratype, same as holotype except general collecting day (USNMENT01377192); 1F, 1 eggcase, same as holotype except general collecting day, 1.5 feet above ground in a log leaning against tree (USNMENT01377193); 2F, same as holotype except hand collected in litter ~6 feet off ground in the leaf bases of Pandanus (USNMENT01377194, USNMENT01377185); 1F, Fianarantsoa, Parc National Andrigitra, 34 km S Ambalavao, 22°08'48.9"S, 46°57'03.4"E, 1580 m, 7 Jan 2009, primary montane rainforest, hand collected under dead log, H.Wood (USNMENT01377186).

Etymology.

The specific name is a patronym to honor Dr. Luke Macaulay for his help collecting palpimanoid spiders.

Diagnosis.

Male is distinguished from other " bourgini group" species except E. milloti sp. n. and E. pauliani (and presumably E. milajaneae sp. n.) by the presence of a lateral process on the conductor (Fig. 14 G–I, asterisk), which is narrow in E. lukemacaulayi and E. milloti (Fig. 14H). Males are distinguished from E. milloti sp. n. by lacking the quarter-moon-like-shape of the palpal bulb in E. milloti (Fig. 17 D–L). Eriauchenius lukemacaulayi sp. n., E. milajaneae sp. n., and E. milloti sp. n. (and presumably E. pauliani ) females are distinguished from other " bourgini group" species by the enlargement of the posterior bar. While this bar is present in other " bourgini group" species, in E. lukemacaulayi sp. n., E. milajaneae sp. n., and E. milloti sp. n. this bar is large and curved into a u-shape. In E. lukemacaulayi sp. n., either end of this bar extends anterior just past the bottom of the “wings” (Fig. 14B), whereas in E. milajaneae sp. n. and E. milloti sp. n. the curved bar goes at least to the middle of the “wings” (Figs 16B, 17B). Eriauchenius lukemacaulayi sp. n. females are also distinguished by the rounded posterior elongation of the FSGP that curves to the dorsal (Fig. 14F, arrow).

Description.

Male holotype (USNMENT01377191, from Parc National Andrigitra, Madagascar). Total length 2.38, carapace 1.05 long, 0.97 wide. Abdomen 1.30 long, 1.47 high. Carapace tilt angle 63.59°, tilt height (CtH) 2.29, constriction 0.55, head length 1.03, neck length 1.04. CtH divided by carapace length 2.18. Cephalon with AME on a large bulge and 4 post-ocular spines on the crown of the cephalon, not on protrusions, and with 1 small spine between the LE and median eyes (on each side, for a total of 2). Chelicerae 1.99 long, and with a spine 0.27 from base of chelicerae and projecting perpendicular to the cheliceral cuticle. Femur I 2.56 long. Sternum 0.66 long, 0.44 wide. Carapace, chelicerae, sternum, and legs reddish brown with white setae. All legs with parts that are lighter brown and parts with darker annulations. Abdomen dark brown mottled with yellowish white spots and interspersed with white setae. Pedipalpal bulb with a membranous sac above the base of the embolus on the retrolateral side, with a greatly exposed embolus that is encircled by the conductor as conductor tapers off (Fig. 14 D–I). Conductor with a constriction, followed by a narrow, curved process (Fig. 14 G–I, asterisk) and a bulge (Fig. 14H, arrow). Embolus broad and dark (Fig. 14 G–I).

Female paratype (USNMENT01377192). Total length 2.42, carapace 1.00 long, 0.93 wide. Abdomen 1.34 long, 1.56 high. Carapace tilt angle 65.6°, tilt height (CtH) 2.18, constriction 0.53, head length 0.97, neck length 1.04. CtH divided by carapace length 2.18. Cephalon as in male. Chelicerae 2.04 long, and with short spine 0.37 from base of chelicerae and projecting downward (Fig. 14A). Femur I 2.40 long. Sternum 0.63 long, 0.44 wide. Colours as in male, expect anterior of abdomen dark brown with yellowish spots and posterior of abdomen mostly yellowish white with some white patches (Fig. 14A). Female genitalia FSGP with a posterior elongation that curves dorsally (Fig. 14F, arrow), and with lateral bulges at the base of each “wing” (Fig. 14B), with a large U-shaped posterior bar that extends just past the posterior portion of the “wings” (Fig. 14B), with poreplates in one group on each lateral side of the bursa anterior (Fig. 14C).

Variation.

Total length 2.17-3.09 (females; n=5); Carapace length 1.01-1.06 (females; n=5); Femur I 2.37-2.55 times the length of carapace in females (n=5). CtH divided by carapace length 2.09-2.25 in females (n=5). Average femur I length 2.48 (females; n= 5).

Natural history.

Specimens were collected in leaf litter, in and under logs and through beating vegetation in primary rainforest from 1580-1830 m in elevation.

Distribution.

Known only from Parc National Andrigitra in southeast Madagascar (Fig. 32).