Mesabolivar guaycolec, Huber, 2018

Huber, Bernhard A., 2018, The South American spider genera Mesabolivar and Carapoia (Araneae, Pholcidae): new species and a framework for redrawing generic limits, Zootaxa 4395 (1), pp. 1-178 : 86-90

Mesabolivar guaycolec sp. n.

Figs 323–324 , 359–364 , 372–373

Mesabolivar “CAS 344”: Huber 2014: 139.

Diagnosis. Easily distinguished from most known congeners (except M. xingu , M. amanaye ) by series of parallel ridges ventrally on procursus ( Fig. 360 ). From M. xingu and M. amanaye by armature of male chelicerae ( Figs 361–362 ; three pairs of frontal processes of distinctive shape and in distinctive pattern), and by shape of epigynum (square-shaped, with sclerotized round internal pouch visible through cuticle; Figs 363 , 372 ) (female of M. xingu unknown).

Etymology. The specific name is derived from the type locality; noun in apposition.

Type material. ARGENTINA: Formosa: ♂ holotype, CAS (9058810), 5♂ 4♀ paratypes, CAS (9027305), 25 km N Formosa, Estancia Guaycolec [25.985°S, 58.16°W, 185 m a.s.l.], 26.ii.–10.iii. 1999 (S.L. Heydon, J.M. Ledford).

Other material. None

Description. Male (holotype)

MEASUREMENTS. Total body length 3.4, carapace width 1.4. Distance PME-PME 130 µm, diameter PME 120 µm, distance PME-ALE 100 µm, distance AME-AME 30 µm, diameter AME 50 µm. Sternum width/length: 0.95/ 0.55. Leg 1: 45.6 (11.7 + 0.5 + 11.5 + 19.9 + 2.0), tibia 2: 7.2, tibia 3: 5.2, tibia 4: 6.9; tibia 1 L/d: 88. Femora 1–4 width (at half length): 0.20, 0.20, 0.18, 0.18.

COLOR (in ethanol). Carapace ochre-yellow, with brown median mark including ocular area; clypeus not darkened; legs light brown, tips of femora and tibiae whitish, slightly darker rings on femora (subdistally) and tibiae (proximally and subdistally); abdomen pale gray, with darker internal marks dorsally and laterally, light brown mark in front of gonopore.

BODY. Habitus as in Figs 323–324 ; ocular area raised; carapace with distinct median furrow; clypeus and sternum unmodified.

CHELICERAE. With three pairs of frontal apophyses; only most proximal pair visible in lateral view ( Figs 361– 362 ).

PALPS. As in Figs 359–360 ; coxa with retrolateral apophysis; trochanter barely modified; femur with retrolateral process proximally, widened distally; procursus with ~7 ventral parallel ridges, proximal ridges indistinct, procursus tip distinctive; genital bulb process mostly unsclerotized, with fine sclerotized tip.

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 2%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~30 pseudosegments, indistinct.

Male (variation). Tibia 1 in three other males: 9.7, 11.5, 16.9.

Female. In general similar to male. Tibia 1 in three females: 7.3, 8.2, 8.2. Epigynum as in Figs 363 , 372 ; anterior plate square-shaped, with medially slightly protruding posterior margin and sclerotized round internal pouch visible through cuticle, without external pocket; posterior plate large but weakly sclerotized and barely visible. Internal genitalia as in Figs 364 , 373 , with large pore-plates, distinctive posterior folds, and internal pouch originating from uterus externus and directed towards ventral cuticle.

Distribution. Known from type locality in Formosa Province ( Argentina) only ( Fig. 735 ).

Figures

FIGURE 735. Known distribution of the Mesabolivar xingu group.

FIGURES 315–326. Live specimens and habitus photos, Mesabolivar spinulosus group and M. xingu group. 315–318. M. spinulosus (Mello-Leitão, 1939), males from Campina Grande and Furna Feia Cave, females from Queimadas and Pinga Cave (feeding on caterpillar).319. M.murici sp. n., male from Murici. 320–321. M. serrapeladasp. n., male and female from Serra Pelada.322.M.amanayesp.n., male fromMarabá (ZFMK Ar19169).323–324.M.guaycolecsp.n.,male in dorsalandlateral views (CAS 9027305). 325–326.M.rudilapsi Machado et al., 2007, male and female from St. Hilaire/Lange.

FIGURES359–364. Mesabolivar guaycolecsp. n. (CAS 9027305).359–360.Left male palp, prolateral andretrolateral views. 361–362. Male chelicerae, lateral and frontal views. 363. Epigynum, ventral view. 364. Cleared female genitalia, dorsal view. Scale lines:0.5 (359–362), 0.3 (363–364).

FIGURES 369–377. Female epigyna and cleared female genitalia, Mesabolivar xingu group. 369–371. M. amanaye sp. n., epigynum in ventral and lateral views, cleared female genitalia in dorsal views (ZFMK Ar 19170).372–373. M. guaycolec sp. n., epigynum in ventral view and cleared female genitalia in dorsal view (CAS 9027305). 374–377. M. rudilapsi Machado et al., 2007, epigynum in frontal, lateral and ventral views, and cleared female genitalia in dorsal view (ZFMK Ar19172).