The Andean Goblin Spiders of the New Genera Niarchos and Scaphios (Araneae, Oonopidae)
ABSTRACT A new genus, Niarchos, is established for a group of 22 new species from the Andean regions of Colombia, Ecuador, and Peru. Although the males of most of these species are obviously gamasomorphines, with a well-developed dorsal abdominal scutum, that scutum is reduced, in the males of two species, to just a narrow, sclerotized, longitudinal strip that covers only the cardiac area and is fused anteriorly to the epigastric scutum. Females of all species, in contrast, show no trace whatever of a dorsal abdominal scutum, have only short and lightly sclerotized epigastric and postepigastric scuta, and could therefore easily be misidentified as oonopines. Four species groups are recognized within the genus, each characterized by a distinctive form of male palp; the four groups are united by the presence of a triangular, posteriorly directed anterior projection on the male endites as well as by the sexual dimorphism in scutum morphology, reduced posterior eyes, and an unusual leg spination pattern (with spines absent on the anterior legs and present only as slightly enlarged but darkened macrosetae on tibiae, and sometimes metatarsi, III and/or IV). The cotopaxi group includes eight species, six from western Ecuador (N. cotopaxi, N. barragani, N. keili, N. baehrae, N. tapiai, and N. elicioi) and two from southwestern Colombia (N. wygodzinskyi and N. florezi); males of this group are united by a unique retroventral projection on the male palpal bulb. The scutatus group includes seven species from eastern Ecuador (N. scutatus, N. ramirezi, N. bonaldoi, N. vegai, N. santosi, N. michaliki, and N. ligiae); males of this group are united by an embolar base bent at a right angle at about half its length. The loja group includes two species from southern Ecuador and northern Peru (N. loja and N. foreroi) in which the embolus is elongated. The palenque group includes two species from western Ecuador (N. palenque and N. facundoi) in which the distal portion of the embolus is short and translucent. Three Ecuadorean species known only from females (N. grismadoi, N. matiasi, and N. rheimsae) are left unplaced, but apparently represent at least one additional, relatively widespread species group. A second new genus, Scaphios, is described for a group of seven new species from Ecuador (S. yanayacu, S. napo, S. cayambe, S. wagra, S. jatun, S. orellana, and S. puyo), plus one species from southwestern Colombia (S. planada), that resemble those of Niarchos in dorsal scutum morphology and leg spination, but have fully developed posterior eyes, a laterally directed anterior projection on the male endites, and a subdistally originating, sinuous embolus. Males of S. orellana also have reduced dorsal and postepigastric abdominal scuta, but (unlike the Niarchos males with reduced scuta) the dorsal scutum is separate from the epigastric scutum. A shared pattern of sexual dimorphism in ventral pedicel sclerite morphology suggests that Niarchos and Scaphios are sister groups.
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ABSTRACT: The goblin spider genus Pescennina Simon has been known only from females of its type species from Venezuela, whereas the more recently described genus Marsupopaea Cooke has been known only from males taken in Colombia. Discovery of the missing sexes, in both cases, indicates that these spiders belong to the Scaphiella complex; males have dorsal abdominal scuta that are absent in females. The presence, in the males of both type species, of a terminal, coiled embolus that can be held in an excavated “pouch” at the anterior edge of the sternum and is matched by coiled anterior ducts in the female genitalia, suggests that these taxa are congeneric. Marsupopaea is therefore newly synonymized with Pescennina, and its type species, M. sturmi Cooke, is placed as a junior synonym of P. cupida (Keyserling). Species of Pescennina occur widely in North, Central, and South America; many are apparently ant mimics, with color patterns (and sometimes a constricted abdomen) that enhance their antlike appearance. Although most of the species seem to be ground dwelling, with the extremely narrow geographic ranges typical of goblin spiders, at least four species inhabit the forest canopy, and at least one of those species is much more widespread. Males of the type species, P. epularis Simon, and females of P. cupida (Keyserling) are described for the first time; 16 new species are described: P. iviei, P. gertschi, P. sumidero, and P. ibarrai from Mexico; P. murphyorum from Nicaragua and Costa Rica; P. viquezi from Costa Rica; P. laselva from Costa Rica and Panama; P. fusca from Panama; P. arborea from Panama, Colombia, and Ecuador; P. magdalena and P. sasaima from Colombia; P. orellana from Ecuador; P. piura and P. loreto from Peru; P. grismadoi from Bolivia; and P. otti from southern Brazil.American Museum Novitates 05/2011; DOI:10.1206/3716.2 · 1.64 Impact Factor
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ABSTRACT: A new genus, Paradysderina, is established for a speciose group of Andean goblin spiders belonging to the Dysderina complex. Members of Paradysderina resemble those of Scaphidysderina Platnick and Dupérré in having the dorsal abdominal scutum of females either greatly reduced or entirely absent, but lack the highly crenulated sternum characteristic of Scaphidysderina and have instead a distinctively flattened, rugose sternal surface. Males of various species of Paradysderina show a wide range of remarkable autapomorphies, including projections at the sides of the clypeus and various kinds of excavations and projections on or between the chelicerae. Several species share the highly unusual occurrence of asymmetry between the left and right male pedipalps; in some species the asymmetry involves the size of the palpal bulb, but in those and other cases, the embolus structure also differs consistently between the two sides, to such an extent that if the left and right palps were studied in isolation, they would be considered to belong to different species. Dysderina globosa (Keyserling) from Colombia and D. montana (Keyserling) from Peru are transferred to Paradysderina, and their males are described for the first time. A total of 52 new species are described, including 26 from Peru (P. watrousi, P. consuelo, P. excavata, P. silvae, P. malkini, P. maldonado, P. asymmetrica, P. apurimac, P. convencion, P. macho, P. tambopata, P. schizo, P. wygodzinskyi, P. newtoni, P. thayerae, P. carpish, P. rothae, P. tabaconas, P. sauce, P. piura, P. tambo, P. fatima, P. bagua, P. yasua, P. loreto, and P. pithecia), 15 from Ecuador (P. zamora, P. lostayos, P. puyo, P. hermani, P. yanayacu, P. baehrae, P. righty, P. centro, P. fusiscuta, P. lefty, P. vlad, P. yasuni, P. dracula, P. pecki, and P. sucumbios), and 11 from Colombia (P. imir, P. pinzoni, P. leticia, P. pira, P. vaupes, P. huila, P. chingaza, P. boyaca, P. carrizal, P. monstrosa, and P. chinacota); P. loreto is also recorded from far western Amazonas, Brazil. A second new genus, Semidysderina, is established for species that share with Scaphidysderina and Paradysderina the absence of a dorsal scutum in females and a spinneret scutum in both sexes, but differ in having a groove connecting the posterior spiracles. Six new species of Semidysderina are described from Colombia (S. lagila, S. kochalkai, S. donachui, S. marta, S. mulleri, and S. sturmi). At least four of these species, from the Sierra Nevada de Santa Marta, are remarkable for the retention of a distinct seam between the male palpal cymbium and bulb.Bulletin of the American Museum of Natural History 01/2012; DOI:10.1206/771.1 · 6.64 Impact Factor
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ABSTRACT: Based on a survey of a wide variety of oonopid genera and outgroups, we hypothesize new synapomorphies uniting the Oonopidae (minus the South African genus Calculus Purcell, which is transferred to the Orsolobidae). The groundplan of the tarsal organ in Oonopidae is hypothesized to be an exposed organ with a distinctive, longitudinal ridge originating from the proximal end of the organ, and a serially dimorphic pattern of 4-4-3-3 raised receptors on legs I–IV, respectively. Such organs typify the diverse, basal, and ancient genus Orchestina Simon. Several other genera whose members resemble Orchestina in retaining two plesiomorphic features (an H-shaped, transverse eye arrangement and a heavily sclerotized, thick-walled sperm duct within the male palp) are united by having tarsal organs that are partly (in the case of Cortestina Knoflach) or fully capsulate (in the case of Sulsula Simon, Xiombarg Brignoli, and Unicorn Platnick and Brescovit). The remaining oonopids are united by the loss of the heavily sclerotized palpal sperm duct, presumably reflecting a significant transformation in palpal mechanics. Within that large assemblage, a 4-4-3-3 tarsal organ receptor pattern and an H-shaped eye arrangement seem to be retained only in the New Zealand genus Kapitia Forster; the remaining genera are apparently united by a reduction in the tarsal organ pattern to 3-3-2-2 raised receptors on legs I–IV and by the acquisition of a clumped eye arrangement. Three subfamilies of oonopids are recognized: Orchestininae Chamberlin and Ivie (containing only Orchestina; Ferchestina Saaristo and Marusik is placed as a junior synonym of Orchestina), Sulsulinae, new subfamily (containing Sulsula, Xiombarg, Unicorn, and Cortestina), and Oonopinae Simon (containing all the remaining genera, including those previously placed in the Gamasomorphinae). The type species of Sulsula and Kapitia, S. pauper (O. P.-Cambridge) and K. obscura Forster, are redescribed, and the female of S. pauper is described for the first time. A new sulsuline genus, Dalmasula, is established for Sulsula parvimana Simon and four new species from Namibia and South Africa.American Museum Novitates 02/2012; · 1.64 Impact Factor