Mecolaesthus Simon 1893
Creators: name: Huber, Bernhard A.
name: Villarreal, Osvaldo
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Mecolaesthus

description: Mecolaesthus Simon, 1893
Mecolaesthus / Mecoloesthus Simon 1893b: 482.
Type species: M. longissimus Simon, 1893.
Falconia González-Sponga, 2003: 94. Name preoccupied, replaced by Ayomania González-Sponga, 2005 and by Venezuela Koçak & Kemal, 2008. Type species: F. multidenticulata González-Sponga, 2003. Synonymized in Huber et al. (2014a).
Queliceria González-Sponga, 2003: 96.
Type species Q. discrepantis González-Sponga, 2003. New synonymy.
Sanluisi González-Sponga, 2003: 100.
Type species: S. puntiaguda González-Sponga, 2003. Synonymized in Huber et al. (2014a).
Ayomania González-Sponga, 2005: 108. Replacement name for Falconia González-Sponga, 2003; see Falconia above.
Venezuela Koçak & Kemal, 2008: 4. Unjustified replacement name for Falconia González-Sponga, 2003; see Falconia above.
Carbonaria González-Sponga, 2009: 2.
Type species: C. cordiformis González-Sponga, 2009. Synonymized in Huber et al. (2014a).
Maimire González-Sponga, 2009: 4.
Type species: M.tuberculosa González-Sponga, 2009. Synonymized in Huber et al. (2014a).
Nasuta González-Sponga, 2009: 6.
Type species: N. grandis González-Sponga, 2009. Synonymized in Huber et al. (2014a).
Moraia González-Sponga, 2011b:43.
Type species: M.niquitanus González-Sponga, 2011. Synonymized in Huber et al. (2014a).
Mecoloesthus – Bonnet 1957: 2742. — Huber 2000: 255.
Justification of synonymy
The type material of Queliceria discrepantis González-Sponga, 2003 was reexamined, as well as new material collected at the type locality. Morphologically, this species strongly resembles several geographically close species of Mecolaesthus (M. cornutus Huber, 2000; M. tabay Huber, 2000; M. mucuy Huber, 2000) in its general habitus and carapace coloration (distinctive lateral dark marks restricted to anterior half), and males show the principal putative synapomorphy of the genus (inflated carapace). Preliminary molecular data (J.J. Astrin, B.A. Huber, unpubl. data) also support a close relationship with the congeners listed above and show Queliceria discrepantis as deeply nested among other Venezuelan Mecolaesthus.
Notes
With now 30 Venezuelan species (14 previously described +16 new), Mecolaesthus is the most speciesrich pholcid genus in Venezuela. Only six species have been described from neighboring countries and regions: Trinidad (1), Lesser Antilles (3), Colombia (1), and Brazil (1). This suggests that Venezuela is the distributional center of Mecolaesthus, but at least the Colombian pholcid fauna is poorly known and may include a large number of species.
Of the 14 Venezuelan species described previously, eleven are treated below. For the remaining three Venezuelan species we do not have new data:
Mecolaesthus azulita Huber, 2000; type locality “ 20 km SE Azulita (ULA Biol. Res. La Carbonera), Mérida, Venezuela ” (Huber 2000) [approximately 8.633° N, 71.366° W]; see Notes under M. cordiformis below.
Mecolaesthus hoti Huber, 2000; type locality only roughly known: “Rio Baria, Dept. Amazonas, Venezuela ” (Huber 2000) [between 0.85° N, 66.43° W and 1.47° N, 66.52° W].
Mecolaesthus puntiagudus (González-Sponga, 2003), type locality Falcón, Sierra de San Luis, Curimagua [approximately 11.172° N, 69.668° W]. The type specimens (2 ♂♂, 8 ♀♀, 1 juv.; MAGS 1432) have been on loan to another researcher and could not be examined.
The ZFMK collection includes material of six further Venezuelan species, from the states La Guaira, Mérida, Trujillo, and Lara. They are not described here because specimens of only one sex are available.
Operational species groups
Venezuelan Mecolaesthus are here divided into three operational species groups, explicitly based on similarity rather than cladistic analysis. In some cases the specific similarities probably reflect phylogenetic relationships, in others not. Such operational species groups provide a preliminary structure for the known species and they facilitate taxon selection in future phylogenetic analyses.
The cornutus group includes the ten species shown in Fig. 1042. Most species in this group look identical in the field (Figs 212–219, 306–311); the lateral dark carapace marks are limited to the anterior part; males do not have a longer abdomen than females; male chelicereae are not provided with modified hairs. Within this group, M. peckorum Huber, 2000; M. tabay Huber, 2000; M. azulita Huber, 2000; and M. cordiformis (González-Sponga, 2009) have extremely similar male chelicerae and female internal genitalia (female of M. azulita unknown). The two species M. chicha Huber sp. nov. and M. parchita Huber sp. nov. fit this group in their morphology but are unusual for their lighter coloration (Figs 277– 282). The two species share strongly banded legs, almost identical procursi and genital bulbs, similar distal cheliceral apophyses and internal female genitalia.
The grandis group includes the eleven species shown in Figs 1043–1044. Males in this group usually have slightly longer abdomens than females (e.g., Figs 429–432); male chelicerae are provided with modified hairs; procursi are distally often bifid, divided into a sclerotized and a membranous part (e.g., Figs 348–350, 390–392); males of several species share sclerotized plates anteriorly on the abdomen, ventrally and/or dorsally (Figs 338, 430). Within this group, M. grandis (González-Sponga, 2009); M. multidenticulatus (González-Sponga, 2003); and M. tuberculosus (González-Sponga, 2009) are almost indistinguishable even by details of their genitalia. The three species were originally described in three different genera but are likely to be closely related. These three species share with three further species [M. niquitanus (González-Sponga, 2011); M. longipes Huber sp. nov.; M. bienmesabe Huber sp. nov.] a distinctive arrangement of male cheliceral apophyses and modified hairs: a pair of large apophyses and a pair of low elevations, both provided with small modified hairs (e.g., Figs 354, 396, 416). A similar arrangement but with much stronger hairs occurs in M. trampa Huber sp. nov. and M. lechosa Huber sp. nov. (Figs 441, 450). The remaining three species (M. arepa Huber sp. nov., M. pusillus Huber sp. nov., M. alegria Huber sp. nov.), share modified hairs on the male chelicerae but do otherwise not easily fit into this group. The two latter species have identical procursi, very similar male chelicerae and genital bulbs, and they share a pair of dark sclerites in the female internal genitalia (Figs 473, 476).
The longissimus group includes the remaining nine Venezuelan species shown in Figs 1045–1046. This group is certainly polyphyletic, and some species may eventually end up in other or new genera (e.g., M. fallax Huber sp. nov., M. limon Huber sp. nov.). Some species (M. longissimus Simon, 1893; M guasacaca Huber sp. nov.; M. yerbatero Huber sp. nov.) share with representatives of the grandis group a bifid procursus tip (Figs 500, 536, 560), but the male chelicerae lack modified hairs. The type species M. longissimus also shares with representatives of the grandis group a longer male than female abdomen. The two species with extremely inflated male prosoma (M. graphorn Huber sp. nov., M. cachapa Huber sp. nov.) remind of congeners in Trinidad and the Lesser Antilles [M. arima Huber, 2000; M. nigrifrons (Simon, 1894); M. lemniscatus (Simon, 1894); M. taino Huber, 2000] but extremely inflated prosomata are also known from undescribed Colombian species (F. Cala Riquelme, pers. comm. 20 Jul. 2017). In addition, the strong intraspecific variability of carapace inflation (e.g., Figs 510–511) makes this a problematic character for phylogeny. The highly aberrant M. fallax is tentatively assigned to Mecolaesthus for the lack of a better solution. Preliminary molecular data (J.J. Astrin, B.A. Huber, unpubl. data) place this species among Mecolaesthus, so it seemed premature to designate a new genus for this species. Finally, M. limon Huber sp. nov. and M. hoti males share the main synapomorphy of the genus (inflated prosoma; Fig. 583) but otherwise the two species appear unique and isolated (male genitalia; in M. limon Huber sp. nov. also female genitalia and spines on male femur 1).
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 71-72, DOI: 10.5852/ejt.2020.718.1101, http://zenodo.org/record/4069574