Litoporus, SIMON, 1893

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 : 292-294

LITOPORUS SIMON, 1893

Litoporus Simon, 1893b: 483 (type species by original designation L. aerius Simon, 1893 ; examined).

DIAGNOSIS: Small (total length ~ 1.5–2

mm), pale, eight-eyed pholcids with oval opisthosoma, extremely long thin legs. Distinguished from similar genera ( Otavaloa , certain Mesabolivar species ) by the high ratio of male femur 1/tibia 1 (femur 1 usually> 1.15 × tibia 1).

DESCRIPTION: Total length ~ 1.5–2 mm. Carapace monochromous ochre-yellow, with distinct thoracic groove, eight eyes on moderately elevated ocular area, AME smallest. Distance PME-ALE large (~ 60–80% of PME diameter). Male clypeus usually un- modified. Male chelicerae variable, typically with 2–3 pairs of rounded, flattened apophyses, or with just one pair of simple, pointed apophyses; without stridulatory ridges. Male palps small in relation to overall size; coxa with (rarely without) retrolateral apophysis, femur usually with large ventrodistal bulge, procursus usually very simple; bulb with usually membranous, relatively complex embolar division. Tarsal organ exposed (examined: L. dimona , n. sp.; lopez , n. sp.). Legs extremely thin and long (leg 1 about 20 × body length; tibia 1 l/d usually> 100), leg 1 always longest, legs 2 and 4 about same length, leg 3 shortest; femur 1 significantly longer than tibia 1; legs without dark rings, femora and tibiae distally whitish; without spines, without curved and vertical hairs; retrolateral trichobothrium of tibia 1 very proximal (at 1–2%); tarsus 1 with ~ 20 to over 30 pseudosegments. Opisthosoma oval, with or without dark markings. Male gonopore without epiandrous spigots (examined: L. dimona : fig. 141, lopez ). ALS with only one piriform gland spigot each (examined: L. dimona , lopez : fig. 172), other spinnerets typical for family.

Female known in only four species, none of them very closely related to type species (see Specific Relationships below). In these species, sexual dimorphism very slight, epigyna differ considerably (see species descriptions below).

MONOPHYLY: The species included share the high ratio of male femur 1/tibia 1; also the extremely long legs, body size, shape, and color. The species closest to the type species (see Specific Relationships below) also share the flattened apophyses on the male chelicerae.

GENERIC RELATIONSHIPS: Litoporus is similar in habitus to Otavaloa , but in that genus the genitalia are very different (palpal femur without ventral bulge, procursus conspicuously curved, different type of armature on male chelicerae). Also very similar in habitus is Mesabolivar (previously Litoporus ) luteus , but in this and related species the femur is hardly longer than the tibia, and the hood on the epigynum is herein used to transfer L. luteus to Mesabolivar . Litoporus may instead be closer to a group of mainly Venezuelan genera that share rounded apophyses or bulges on the palpal femora ( Mecoloesthus , Coryssocnemis , Systenita ). Otherwise, however, these genera appear very different. The close relationship with Pomboa suggested by the cladogram in appendix 2 is based on the large distance between the eye triads (char. 2) and is probably artificial. (Note that one of the three most parsimonious trees found by NONA does not include this sister group relationship.) Whatever the sister group, Litoporus is clearly an element of the New World clade (thoracic groove, large distance PME-ALE, retrolateral coxal apophysis, epiandrous spigots absent, ALS piriform gland spigots reduced to one, exposed tarsal organ).

SPECIFIC RELATIONSHIPS: Three of the species newly described ( L. dimona ; saul , n. sp.; secoya , n. sp.) seem to be closely related to the type species: they share the typical flat, rounded apophyses on the male chelicerae, and have extremely similar procursi. The other species ( L. lopez ; uncatus (Simon) ; manu , n. sp.; pakitza , n. sp.; yucumo , n. sp.) differ considerably in the armature of the chelicerae, and L. uncatus has also a more complicated procursus. These species are therefore assigned tentatively to the genus.

MISPLACED SPECIES: Of the 13 species previously assigned to Litoporus , all but the type species and one species incertae sedis are herein either transferred to other genera, or synonymized [ L. abrahami is correctly placed, but a synonym of L. (previously Coryssocnemis ) uncatus ]. Most species are transferred to Mesabolivar : L. argentinensis , brasiliensis, tandilicus, luteus and its synonyms ( coccineus , fulvus , imbecillus ); L. aberrans is transferred to Chibchea , L. genitalis to Carapoia ; L. iguassuensis to Tupigea ; L. agricola cannot be placed (see appendix 3).

NATURAL HISTORY: There are data on the tentatively assigned L. lopez only (see description of this species below).

DISTRIBUTION: Widely distributed in northern and central South America.

COMPOSITION: The genus as construed here includes 10 nominal species: the type L. aerius , not treated herein (see Huber, 1997b, for redescription); L. uncatus , redescribed below; and the seven species newly described below. The tenth species ( Litoporus agricola Mello-Leitão, 1922 ) is incertae sedis. I have seen further undescribed species from Peru and Bolivia (in MUSM and AMNH) .