Difference between revisions of "Eriauchenius rixi"

Revision as of 16:21, 8 January 2018

Taxonavigation

Ordo: Araneae
Familia: Archaeidae
Genus: Eriauchenius

Name

Eriauchenius rixi Wood & Scharff, 2017 sp. n. – Wikispecies link – ZooBank link – Pensoft Profile

Type material

Male holotype: Madagascar, Fianarantsoa, Parc National Ranomafana, Vohiparara, Piste Touristique, 21°13.6'S, 47°24.0'E, 1000 m, 19 Apr 1998, C. Griswold, D. Kavanaugh, N. Penny, M. Raherilalao, E. Rajeriarison, J. Ranorianarisoa, J. Schweikert, D. Ubick (deposited in CAS; CASENT9012013).

Other material examined

Female paratype, same data as holotype, except 12 and 14 Apr 1998 (CASENT9012346).

Etymology

The specific name is a patronym to honor Dr. Michael Rix for his work describing Australian archaeids and examining their biogeographic patterns and evolutionary relationships.

Diagnosis

Males are distinguished from other “bourgini group” species by having a sharp process at the base of the pedipalpal tegulum (Fig. 20G–I, arrows). Females are distinguished from other “bourgini group” species by having the posterior bar curved towards the dorsal rather than the anterior (Fig. 20C), by having large broad “wings” and a narrow posterior elongation that is blunt at the end (Fig. 20C, arrow).

Description

Male holotype (CASENT9012013, from Parc National Ranomafana, Madagascar). Total length 2.01, carapace 0.88 long, 0.79 wide. Abdomen 1.05 long, 1.23 high. Carapace tilt angle 64.8°, tilt height (CtH) 1.51, constriction 0.43, head length 0.80, neck length 0.71. CtH divided by carapace length 1.72. Cephalon with AME on large bulges, and with 4 short post-ocular spines on the crown, not on protrusions, and 1 short spine between the LE and median eyes (on each side, for a total of 2). Chelicerae 1.44 long, and with a short spine 0.34 from base of chelicerae. Femur I 1.99 long. Sternum 0.56 long, 0.34 wide. Carapace, chelicerae, and sternum dark reddish brown with white setae. Coxae and legs yellowish brown, with darker annulations on tibiae and metatarsi. Abdomen mottled brown and beige, with tufts of white setae (Fig. 20A). Pedipalpal tegulum with a sharp process (Fig. 20G–I, arrow), bulb with a membraneous sac on the retrolateral side, with conductor encircling the broad, thick embolus (Fig. 20D–L). SC present and long and thin (Fig. 20D–L). MA present and a dark horn-like process (Fig. 20G, I, J, L).
Female paratype (CASENT9012346). Total length 2.46, carapace 0.95 long, 0.86 wide. Abdomen 1.43 long, 1.82 wide. Carapace tilt angle 63.4°, tilt height (CtH) 1.82, constriction 0.50, head length 0.91, neck length 0.84. CtH divided by carapace length 1.92. Cephalon as in male. Chelicerae 1.62 long, and with short spine 0.37 from base of chelicerae. Femur I 2.06 long. Sternum 0.61 long, 0.37 wide. Colors as in male. Female genitalia FSGP with broad wings, a narrow, blunt posterior elongation (Fig. 20B, arrow); genitalia with a PB, and with poreplates in one group one each side of the bursa anterior (Fig. 20C).

Variation

no other specimens known.

Natural history

Specimens were collected at 1000 m in elevation, likely in rainforest, although not specified on the label.

Distribution

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

Original Description

• Wood, H; Scharff, N; 2017: A review of the Madagascan pelican spiders of the genera Eriauchenius O. Pickard-Cambridge, 1881 and Madagascarchaea gen. n. (Araneae, Archaeidae) ZooKeys, (727): 1-96. doi

Images

Figure 20. Eriauchenius rixi sp. n. A male (holotype, CASENT9012013) habitus, lateral view, image reversed B–C female (CASENT9012346) internal genitalia B dorsal view, arrow showing the FSGP narrow posterior elongation C anterior view D–L male pedipalpal bulbs (holotype, CASENT9012013) D–F right bulb, image reversed G–L left bulb, arrow showing the sharp process on the tegulum base D, G, J prolateral view E, H, K ventral view F, I, L retrolateral view. Scale bars: 1 mm (A); 0.25 mm (B, D).  Figure 32. Distribution map for Eriauchenius species. ** The distribution for E. pauliani is an approximation as the holotype does not have latitude/longitude data.