Eriauchenius mahariraensis (Lotz, 2003) Lotz, 2003

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 mahariraensis (Lotz, 2003) comb. n. Figs 15, 32

Afrarchaea mahariraensis Lotz, 2003: 237, figs 5A, 8 A–B.

Type material.

Female holotype: as Afrachaea mahariraensis Lotz, 2003, from MADAGASCAR, Ranomafana N.P., Maharira, trail, 10 Apr 1992, sifting, Emile for Kariko/Roth (examined, deposited in MCZ).

Other material examined.

MADAGASCAR: male paratype, Fianarantsoa, Parc National Ranomafana, Vohiparara, 3.6 km W Ranomafana, 21°14.243'S, 47°23.842'E, 1150 m, 13-14 Jan 2009, primary montane rainforest, sifting dead ferns on ground, C. Griswold, A. Saucedo and H. Wood (USNMENT01377173)

Diagnosis.

Males and females are distinguished from other Eriauchenius , except E. ratsirarsoni and E. sama sp. n., by the presence of 4 small spines on the apex of the cephalon, and having the cheliceral spine pointing perpendicular (as in Fig. 11L). In the holotype female the cheliceral spine is broken off, but the socket shape suggests the spine would be at a perpendicular orientation as it is in the paratype male. Eriauchenius mahariraensis is also distinguished from other Eriauchenius males, by having membranous tissue close to the conductor tip (Fig. 15 E–L), and other Eriauchenius females by having a very reduced FSGP with the width divided by height greater than 2 (Fig. 15B).

Description.

Female holotype (MCZ, from Parc National Ranomafana, Madagascar). Total length 1.91, carapace 0.74 long, 0.69 wide. Abdomen 1.06 long, 1.24 high. Carapace tilt angle 64.4°, tilt height (CtH) 1.32, constriction 0.44, head length 0.68, neck length 0.64. CtH divided by carapace length 1.77. Cephalon with AME on a small bulge. Cephalon with 4 small post-ocular spines (one is missing or broken off) on the crown of the cephalon, not on protrusions, and 1 spine between the LE and AME (on each lateral side, for a total of 2, but broken off on the right side). Chelicerae 1.33 long, and with a spine 0.24 from base of chelicerae, however, the spines are broken off and only the socket remains; the socket shape suggests the spines would projecting perpendicular to the cheliceral cuticle. Femur I 1.46 long. Sternum 0.51 long, 0.35 wide. Carapace, chelicerae, sternum, and legs reddish brown with white setae; patellas lighter brown. Abdomen anterior dark brown with light circular patches and posterior light tan; abdomen with white and brown setae (Fig. 15A). Female genitalia with a small and simple FSGP, with “wings” highly reduced; posterior bar is present, but the dissection was such that it remains attached to the abdomen and is not visible in Fig. 15 B–C; with poreplates in one small group on each lateral side of the bursa anterior, and a small sclerotized piece on the ventral side of the poreplates (Fig. 15C, arrow).

Male paratype (USNMENT01377173). Total length 1.64, carapace 0.78 long, 0.68 wide. Abdomen 0.83 long, 0.97 high. Carapace tilt angle 66.7°, tilt height (CtH) 1.31, constriction 0.44, head length 0.72, neck length 0.61. CtH divided by carapace length 1.69. Cephalon with AME on a small bulge, and with 4 small post-ocular spines (one is missing or broken off) on the crown of the cephalon, and 1 spine between the LE and AME (on each side, for a total of 2). Chelicerae 1.23 long, and with small spine 0.17 from base of chelicerae (Fig. 15A). Femur I 1.63 long. Sternum 0.49 long, 0.32 wide. Cephalothorax colors as in female. Abdomen mostly light tan, but mottled with dark brown areas that have light circular patches; with white and brown setae; posterior of abdomen with bright white areas. Pedipalpal bulb with a small membraneous sac above the embolus base, with a greatly exposed broad and dark embolus that is encircled by the conductor (Fig. 15 D–L). Conductor with a membranous area at the distal end that swirls around the embolus (Fig. 15 D–L).

Variation.

no other known material.

Natural history.

Male specimen was collected at 1150 m in elevation. Both specimens were collected in montane rainforest by general sifting, or sifting dead ferns on the ground.

Distribution.

Known only from Parc National Ranomafana in central-eastern Madagascar (Fig. 32).

Nomenclatural remarks.

E. mahariraensis and E. sama sp. n. both occur at Parc National Ranomafana. Males and females were associated based on body size and carapace shape.