Madagascarchaea rabesahala, 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

Madagascarchaea rabesahala sp. n. Figs 25, 33

Type material.

Male holotype: MADAGASCAR, Antananarivo, 3 km 41° NE Andranomay, 11.5 km 147° SSE Anjozorobe, 18°28'24"S, 47°57'36"E, 1300 m, 5-13 Dec 2000, montane rainforest, beating and sweeping, Fisher, Griswold et al. (deposited in CAS: CASENT9004011).

Other material examined.

MADAGASCAR: Female paratype, same data as holotype except beating low vegetation (CASENT9003843); 1M, together with the holotype (CASENT9004011); 3M,3F,1juv, same data as holotype except general collecting (CASENT9004086); 1F,1juv,1 eggcase, Toamasina, Station Forestier Analamazaotra, administered by Mitsinjo, 0.75 km N Andasibe, 18°55.783'S, 48°24.696'E, 964m, 2 Feb 2009, primary montane rainforest, sifting litter around logs, dead fern fronds, and at base of traveler’s palm, H. Wood (USNMENT01377200).

Etymology.

The specific name is a noun in apposition and commemorates Gisèle Rabesahala, a Malagasy activist and politician.

Diagnosis.

Distinguished from all other archaeids, except M. vadoni , M. legendrei , M. fohy sp. n., and M. borimontsina (presumably, because the male is unknown) by having a retrolateral apophysis on the distal side of the male pedipalpal femur and patella (see fig. 12B in Wood 2008), and because the FSGP is highly reduced and lacks “wings” (Fig. 25B). M. rabesahala is distinguished from M. vadoni by having the cephalic spines not on protrusions (Fig. 24A), rather than the protrusions seen in M. vadoni (see fig. 18C in Wood 2008); from M. borimontsina by having less than 6 teeth on the cheliceral retromargin, by having a rounded bulge that the AME rests upon, and by lacking a bulge on the posterio-basal side of the chelicerae (see fig. 18D in Wood 2008); from M. fohy sp. n. by lacking a heavily sclerotized rod-shaped sclerite on the palpal bulb (Fig. 23H,J, arrow), and by lacking a retrolateral cymbial protrusion (Fig. 25C, arrow); and from M. legendrei by having a cephalon that is not as perfectly rounded (compare cephalon shape in Figs 24A, 25A), and by having a larger and more sclerotized triangular basal portion of the conductor (compare basal “c” in Figs 24G, 25G).

Description.

Male holotype (CASENT9004011, from forest close to Andranomay, Madagascar). Total length 1.66, carapace 0.73 long, 0.61 wide. Abdomen 0.90 long, 1.07 high. Carapace tilt angle 62.4°, tilt height (CtH) 1.42, constriction 0.39, head length 0.63, neck length 0.71. CtH divided by carapace length 1.95. Cephalon with AME on large bulge, and with 6 short post-occular spines at the crown, not on protrusions, and lacking spine between the LE and AME. Chelicerae 1.44 long, and with a small spine 0.33 from base of chelicerae and projecting downward (Fig. 25A). Femur I 2.01 long. Sternum 0.46 long, 0.30 wide. Carapace, chelicerae, sternum and legs reddish brown with white setae. Legs with darker annulations on tibiae and metatarsi. Abdomen dark brown with lighter circular patches throughout, with white setae (Fig. 25A). Pedipalpal bulb of the " vadoni group" form (Fig. 25 D–I): pedipalpal bulbs elongated with the conductor swirling around a mostly membraneous embolus; conductor base triangular (Fig. 25D), with remainder of conductor elongate and cradling embolus, and with a curved tip; MA translucent and fans out (Fig. 25 E–F,H–I). Cymbium lacks retrolateral protrusion (Fig. 25C, arrow).

Female paratype (CASENT903843). Total length 1.91, carapace 0.80 long, 0.67 wide. Abdomen 1.11 long, 1.55 high. Carapace tilt angle 62.3°, tilt height (CtH) 1.55, constriction 0.42, head length 0.78, neck length 0.82. CtH divided by carapace length 1.94. Cephalon as in male, except spine between LE and AME present. Chelicerae 1.61 long, and with a small spine 0.34 from base of chelicerae and projecting downward (Fig. 25A). Femur I 1.97 long. Sternum 0.49 long, 0.32 wide. Colors as in male. Genitalia of the " vadoni -group" form (Fig. 25B): with one group of poreplates on each side of the bursa anterior; with FSGP highly reduced, lacking “wings.”

Variation.

Total length 1.56-1.66 (males; n=5), 1.91-2.07 (females; n=4); Carapace length 0.72-0.75 (males; n=5), 0.74-0.81 (females; n=4); Femur I 2.69-2.86 times the length of carapace in males (n=5), 2.38-2.69 in females (n=4); CtH divided by carapace length 1.93-2.12 in males (n=5), 1.94-2.15 in females (n=4); Average femur I length 2.03 in males (n=5), 1.96 in females (n= 4). The spine between the LE and AME is present is 3 males out of 5, and 4 females out of 4.

Natural history.

Specimens were collected in montane rainforest from 960-1300 m in elevation by beating low vegetation, by sifting litter, by beating and sweeping, and by general collecting.

Distribution.

Known only from central eastern Madagascar (Fig. 33).