Chibchea, HUBER, 2000

HUBER, BERNHARD A., 2000, New World Pholcid Spiders (Araneae: Pholcidae): A Revision At Generic Level, Bulletin of the American Museum of Natural History 2000 (254), pp. 1-348 : 162-164

CHIBCHEA , NEW GENUS

TYPE SPECIES: Chibchea ika , new species.

ETYMOLOGY: The generic name honors the Chibcha Indians and their surviving acculturated descendants. The Chibcha are a people native to the high plateau of Colombia who declined rapidly after the arrival of the Spaniards and whose dialect had become extinct by the early 1700s. Gender feminine.

DIAGNOSIS: Tiny to medium-sized (total length 1.1 3.6 mm), usually dark pholcids with eight eyes (AME rarely rudimentary or absent), with short to medium-long legs, globular to oval to higher-than-long opisthosoma; distinguished by the short, almost cylindrical segments of the male palp, and by the projections or apophyses on the male cheliceral fangs (figs. 31, 620, 631, etc.; absent in Venezuelan and Chilean representatives and in the Peruvian C. mateo , n. sp., and abiseo , n. sp., which are assigned tentatively; see Specific Relationships below).

DESCRIPTION: Total length usually ~ 2.2 3.6 mm ( C. uru , n. sp., only 1.1 mm). Carapace with distinct thoracic groove (very shallow in C. uru ), ocular area low to moderately elevated, with eight eyes, AME smallest (absent in C. uru ); distance PME- ALE relatively large (usually ~ 60 110% of PME diameter, only 30% in C. uru ). Sternum without humps. Male clypeus unmodified. Basal segment of male chelicerae unmodified or with transverse ridge proximally (e.g., figs. 665, 681), with tiny to large apophyses originating from the fangs (the Venezuelan and Chilean representatives and C. mateo and abiseo have apophyses and/or modified hairs on the basal segments, but unmodified fangs); without stridulatory ridges laterally. Male palpal coxa with retrolateral apophysis (absent in C. mayna , n. sp.), femur short, almost cylindrical, with often very conspicuous retrolateral apophysis basally (e.g., figs. 658, 680); procursus and bulb variable. Tarsal organ exposed (examined: C. ika , n. sp.; salta , n. sp.; araona , n. sp.; picunche , n. sp.). Legs relatively short (leg 1 usually ~ 4 8 × total length; only 2.5 in C. uru , 10 in C. malkini , n. sp., and silvae , n. sp.; tibia 1 l/d usually 30 70; only 9 in C. uru ); leg 1 usually longest, leg 2 about as long as leg 4, leg 3 shortest (in C. uru leg 4 longest: 4123); legs without spines and vertical hairs (only C. silvae with many vertical hairs on metatarsi); sometimes with curved hairs (on femora and/or tibiae + metatarsi); retrolateral trichobothrium of tibia 1 usually at ~ 10 35% (at 51% in C. uru ); tarsus 1 usually with ~ 15 25 pseudosegments (only ~ 10 in C. uru ). Opisthosoma variable in shape, with dark spots dorsally. Male gonopore without epiandrous spigots (examined: C. ika , salta , araona , picunche ). ALS with only one piri- form gland spigot each (examined: C. ika , salta , araona , picunche ), other spinnerets typical for family.

Sexual dimorphism slight. Females often with more distinct dark rings on legs. Epigynum variable in shape.

MONOPHYLY: The species of the coregroup ( C. ika , valle , mayna , salta, aberrans , araona , uru , silvae , malkini ) share the apophyses on the male cheliceral fangs, and the short, cylindrical segments of the male palp. The Venezuelan and Chilean species and C. mateo and abiseo are included tentatively (see Specific Relationships below).

GENERIC RELATIONSHIPS: Two other genera share apophyses on the male cheliceral fangs ( Galapa , Blancoa : figs. 30, 32), but in these the apophyses originate from the bases of the fangs rather than from the middle, and the genitalia are very different. Other than that, only the placement within the New World clade is beyond doubt (large distance PME- ALE, retrolateral coxal apophysis, reduction of epiandrous spigots and ALS piriform spigots, exposed tarsal organ). The close relationship with Carapoia suggested by the cladogram in appendix 2 is based on the presence of curved hairs on the legs and is very probably artificial.

SPECIFIC RELATIONSHIPS: The genus can tentatively be divided into four operational species groups: (1) a possibly monophyletic northern group from Colombia and Ecuador ( C. ika , valle , mayna ) with a sculptured epigynum that is provided with pits or pockets (presumably for the male cheliceral apophyses); C. merida and tunebo have a very distinct armature on the male chelicerae (and lack sexual modifications of the fangs), but they have almost identical procursi, proximal palpal segments, and prosoma shape as the type species, and are therefore included tentatively in this group and in the genus (note that they have been collected very close to the type locality of C. ika , the type species!); (2) a possibly monophyletic southern group from Peru, Bolivia, Argentina ( C. salta, aberrans , araona , uru , silvae , malkini ) with a very conspicuous retrolateral apophysis basally on the femur and a rather pointed retrolateral coxal apophysis on the male palp; additionally, these species share a small, distinctive apophysis on the male palpal trochanter (e.g., figs. 658, 688; absent only in C. uru ), and prominent transverse ridges proximally on the male chelicerae; (3) a Chilean group ( C. picunche , mapuche , elqui ), that lacks the primary synapomorphy of the genus (fang apophyses), but is otherwise very similar (overall size and habitus, leg length, curved hairs on legs), and therefore assigned tentatively to the genus; (4) a Peruvian group ( C. mateo , abiseo ) that is similar and possibly close to the Chilean group.

DISTRIBUTION: Widely distributed in western South America, from Colombia (and possibly eastern Venezuela; see Specific Relationships above) to Argentina (and possibly Chile; see Specific Relationships above). Apparently restricted to the Andean region.

COMPOSITION: The genus as construed here includes 16 named species, 15 of which are new. All 16 species are treated below. I have seen numerous further species from Ecuador, Peru, Bolivia, Paraguay and Chile (AMNH, CAS, MUSM, USNM).