Mecolaesthus piedras Huber 2020, sp. nov.
Creators: name: Huber, Bernhard A.
name: Villarreal, Osvaldo
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Mecolaesthus
Mecolaesthus piedras

description: Mecolaesthus piedras Huber sp. nov.
urn:lsid:zoobank.org:act: CF40549A-34A3-4C69-834A-17B965CE9216
Figs 306–308, 312–320, 331–333, 1042
Diagnosis
Distinguished from known congeners by armature of male chelicerae (Figs 318–319; pair of strong pointed frontal processes), by two distinctive flat elements distally on procursus (Figs 312–314), by genital bulb with distinctive ventral and dorsal sclerites on embolar division (arrows in Fig. 315), by long epigynum widening anteriorly (Fig. 331), and by internal female genitalia (Figs 320, 332–333; strong median sclerite, pore plates on distinctively curved sclerite).
Etymology
The species name refers to the type locality; noun in apposition.
Type material
VENEZUELA – Mérida • ♂ holotype, ZFMK (Ar 21897), Las Piedras, ‘site 1’ (8.8939° N, 70.6448° W), 1710 m a.s.l., forest remnant, 7 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.).
Other material
VENEZUELA – Mérida • 1 ♀ in pure ethanol, ZFMK (Ven20-106), same collection data as for holotype; abdomen moved to holotype.
Description
Male (holotype)
MEASUREMENTS. Total body length 3.0, carapace width 1.25. Distance PME–PME 130 µm; diameter PME 100 µm; distance PME–ALE 110 µm; diameter AME 25 µm; distance AME–AME 25 µm. Leg 1: 24.6 (5.7+ 0.6+5.7+ 10.3 +2.3), tibia 2: 3.6, tibia 3: 2.7, tibia 4: 3.3; tibia 1–4 diameters: 170 µm, 185 µm, 190 µm, 190 µm; tibia 1 L/d: 34.
COLOR (in ethanol). Carapace pale gray, darker brown frontally including ocular area and clypeus, lateral dark bands in anterior part only, median dark mark with radiating lines; sternum dark brown; legs light brown, with darker rings on femora subdistally and on tibiae proximally and subdistally, femora and tibiae with light tips; abdomen pale bluish-gray, dorsally and laterally densely covered with dark bluish marks, ventrally with large brown mark in gonopore area, brown book lung covers, and bluish marks in front of and behind gonopore; without ventral or dorsal anterior brown plates.
BODY. Habitus as in Figs 306–307. Ocular area distinctly raised. Carapace anteriorly with shallow but distinct thoracic groove, posteriorly without groove, not inflated. Clypeus unmodified. Sternum wider than long (0.84/0.68). Abdomen slightly elongated and pointed at spinnerets.
CHELICERAE. As in Figs 318–319, with pair of strong pointed frontal processes, tips slightly diverging.
PALPS. Proximal segments as in M. discrepantis (González-Sponga, 2003) comb. nov. (cf. Figs 321– 322); coxa with strong retrolateral apophysis, trochanter with rounded ventral process, femur proximally with retrolateral process, distally with prominent rounded ventral process, retrolateral trichobothrium of tibia in very distal position; procursus (Figs 312–314) proximally simple, without retrolateral process, small dorsal processes, distally with two distinctive flat elements; genital bulb (Figs 315–317) with distinctive ventral and dorsal sclerites on embolar division, with slender prolateral pointed process.
LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 5%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~35 pseudosegments, mostly distinct. Coxa 4 not modified.
Female
In general similar to male (Fig. 308). Tibia 1 missing. Epigynum (Fig. 331) longer than wide, widening anteriorly, posterior margin strongly sclerotized, internal sclerites partly visible in uncleared specimens. Internal genitalia (Figs 320, 332–333) with strong median sclerite on ventral wall of uterus externus
(not on epigynal plate), pore plates on distinctively curved sclerite, with small round anterior median receptacle.
Distribution
Known from type locality only, in Venezuela, Mérida (Fig. 1042).
Natural history
The two specimens were collected from holes in the ground near an almost dried up stream in a small forest remnant.
description: Published as part of Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), pp. 1-317 in European Journal of Taxonomy 718 on pages 94-97, DOI: 10.5852/ejt.2020.718.1101, http://zenodo.org/record/4069574