The harvestman genus Taracus Simon 1879, and the new genus Oskoron (Opiliones: Ischyropsalidoidea: Taracidae) Shear, William A. Warfel, Joseph G. Zootaxa 2016 4180 1 1 71 7Z5DD Shear Shear [151,412,1741,1767] Arachnida Taracidae Taracus Animalia Opiliones 41 42 Arthropoda species taylori sp. nov. Ischyropsalidoidea     Types.Male holotype, male and four female paratypesfrom Snake Canyon Cave, 9100’ asl,  Schell CreekRange, 13 kmeast-northeast of McGill, in Humboldt-Toiyabe National Forest, White Pine County, Nevada, collected  8 June 2012by S. J. Taylor, T. Gillelandand L. Santisteban, and on  31 October 2011by J. Knight, A. Smithand B. Szukalski; these specimens deposited in the Illinois Natural History Survey. Female paratypefrom the same locality, but collected  28 October 1967by an unknown person; deposited in CAS.   Diagnosis.Only this species and  T. spesavius,  n. sp., are known from Nevada; the latter species occurs to the north in the Ruby Mountains. The two are very close, but  spesaviusdoes not have reduced eyes. The two species also differ in leg length, though the body length is about the same;  taylorihas shorter legs. The chelicerae of  T. tayloriare larger, thicker, and more spiny than in  T. spesavius,and the abdomen is more setose (though setation is quite sparse in both species). Given the isolation of the two mountain ranges by inhospitable sagebrush desert, we hypothesize that the populations are reproductively isolated and therefore constitute species. Future genetic studies can test this hypothesis.   Etymology.The species epithet honors biospeleologist Steven Taylor of the IllinoisNatural History Survey, whose collecting in Great Basin caves has helped to reveal a surprisingly extensive and complex fauna.   Description. Male from Snake Canyon Cave.Total length, 5.4 mm. Carapace dark chestnut brown to black, more lightly sclerotized laterally, marked irregularly with lighter areas; central region strongly domed; midline sulcus closed, does not reach anterior margin of ocularium. Ocularium as wide as long, rounded, higher behind, with few small setae; eyes reduced to about one-half diameter of those of epigean species. Metapelitidium lightly sclerotized, with short row of small setae; sensory cone long, brown, acute ( Figs. 82, 83), inclined forward, then recurved, resting in shallow depression in posterior surface of ocularum. Abomen soft, white, unsclerotized, set with scattered, small, black setae; setae not on sclerotized plaques or tubercles, very lightly sclerotized midline patches on first two areas ( Figs. 84, 85). Ventrally, coxae white to tan, irregularly mottled dark brown. Palpal and first leg coxae brown, with stout setae on distinct tubercles, second to fourth leg coxae pale tan, with strong, black setae not on tubercles. Five or six setae in two groups on lightly sclerotized patches mark presumed position of thoracic sternum. Second coxal endites long, narrow, separate from coxae. Genital operculum apically rounded, heavily setose, pale tan with large, dark brown spots. Venter of abdomen with setae in irregular rows on lightly sclerotized transverse bands marking positions indistinct abdominal sternites. Chelicerae ( Fig. 88) 11.82 mmlong, slender, black. Basal article 5.20 mmlong, 0.44 mmwide (L/W = 11.82); second article 6.24 mmlong, 0.68 mmwide (L/W = 9.18). Basal article with prominent, acute seta-tipped tubercles extending three-quarters of length, dorsal tubercles much smaller; second article with relatively low, rounded setatipped tubercles ranged in about five irregular rows, tubercles more widely spaced distally. Fixed and movable fingers with paired, articulating triangular teeth, narrow, acute tips of fingers cross each other at rest. Palpi ( Fig. 78) dark brown, total length 13.48 mm, typical for genus; trochanter with prominent scattered setatipped tubercles. Lengths of articles as given in Table 13. Legs long, thin; first leg brown, becoming lighter distally, other legs yellowish tan without markings.. Autospasy suture of femur indistinct on legs 1, 3. Tibiae without false articulations, metatarsi of legs 1, 3, 4 with about 15–17 false articulations; leg 2 with numerous very faint false articulations. Total lengths in mm of legs 1–4: 17.28, 27.94. 17.04, 21.95. Measurements of leg articles given in Table 13.   TABLE 13.Lengths in mm of palpal and leg articles of male Taracus taylori.    Femur Patella Tibia Metatarsus Tarsus  Palpus 5.67 2.78 3.81 - 1.22  Leg 1 4.52 1.10 2.52 5.71 3.43  Leg 2 6.09 1.29 4.90 9.71 5.95  Leg 3 3.95 1.09 2.76 5.67 3.57  Leg 4 5.19 1.19 3.57 7.38 4.62 Penis ( Figs. 79–81) 2.54 mmlong, 0.22 mmwide (L/W = 11.54), sides of shaft straight, tapering gradually to slightly twisted, short aculeus; glans not set off by suture; aculeus subtended by crown of few small, acute setae; shaft with few similar scattered setae on either side below glans.  Female from Snake Canyon Cave:As for the male holotype, except as follows. Total length, 5.63 mm( Figs. 82, 83). Cheliceral ( Figs. 86–87) basal article 5.90 mmlong, 0.53 mmwide (L/W = 11.13); second article 7.05 mmlong, 0.84 mmwide (L/W = 8.39). Total length of palpus ( Fig. 77), 14.12 mm. Depression in posterior margin of ocularium that receives sensory cone deeper than in male. Metatarsal false articulations not detectable in metatarsi 2 (podomere very thin). Total lengths in mm of legs 1–4: 17.09, 27.52, 16.02, 21.88; lengths of leg and palpal articles as given in Table 14. Ovipositor typical.   Distribution.Known only from Snake Canyon Cave, White Pine Co., Nevada. Snake Canyon is located at 39°26’54”N, 114°39’00”W, on the west slopes of the Schell Creek Range, near McGill, Nevada. We do not further locate the cave itself because of conservation concerns.   MAP 5.Parts of the states of Idaho, Montana, Oregon and Washingtonand the provinces of British Columbia and Alberta. Filled circles, localities for  Taracus gertschiGoodnight & Goodnight.    MAP 6.Parts of Nevada and Utah. Filled circle, type locality of  Tarcus taylori,  n. sp.; filled triangle, type locality of  T. spesavius,  n. sp.; filled squares, localities for  T. timpanogos,  n. sp.  Notes.The following notes are courtesy of Steve Taylor (pers. comm. 2013). The peak above Snake Canyon reaches 11,073’ asl, but despite the altitude the region is quite dry; larger pines are found only along the canyon floors. The immediate surroundings of the cave are rocky and vegetated by low oak, Mormon tea and sagebrush; there is little or no litter cover. In general the habitat does not appear favorable for  Taracusoutside the cave or higher on the mountain. The cave supports a population of  Neotomapackrats with their middens and feces providing habitat for phorid and sciariid flies as well as fleas; these insects could be prey for  Taracus taylori. We would hypothesize, given the habitat (scanned viaGoogle Earth), that there are not likely to be epigean  Taracuspopulations in the Schell Creek Range. The long legs, reduced eyes and weak abdominal sclerotization of individuals of  T. taylorispeak to moderate troglobiosis, perhaps developed since the last pluvial period ended some 15,000 years ago and increasing drought extinguished surface populations of  Taracus.It remains to be seen if other caves in the Schell Creek Range and indeed in other Great Basin inselbergranges support  Taracuspopulations. 1324487201 1967-10-28 2012-06-08 1967-10-28 CAS S. J. Taylor & T. Gilleland & L. Santisteban & J. Knight & A. Smith & B. Szukalski & Natural History Survey. Female White Pine County Schell Creek Range Snake Canyon Cave 41 42 4 Nevada holotype 1324487188 Idaho, Montana, Oregon and Washington 44 45 1 Idaho, Montana, Oregon and Washington 1324487207 [151,526,1252,1274] Nevada and Utah 44 45 1 Nevada and Utah