Cladistic analysis and taxonomic revision of the genus Karos Goodnight & Goodnight, 1944 (Opiliones, Laniatores, Stygnopsidae) Author Cruz-López, Jesús A. Author Francke, Oscar F. text Zoological Journal of the Linnean Society 2015 2015-11-18 175 4 827 891 http://dx.doi.org/10.1111/zoj.12299 journal article 10.1111/zoj.12299 0024-4082 5339971 KAROS SINGULARIS SP. NOV. ( FIGS 18–20 , 59 , 65F , 61B, H , 62C , 64C ) Type material: MEXICO : Querétaro : ♂ holotype [CNAN- T0723 ( 6.v.2011 ; O. Francke , A. Valdez , C. Santibáñez , J. Cruz , G. Contreras and R . Monjaraz )], ( 21°11′57.19″N , 99°13′06.78″W ) Municipio Landa de Matamoros , Km 7.5 of the road to La Lagunita – Tilaco . Hidalgo : 1 ♂ paratype [ CNAN-T0724 ( 6.xi.2010 ; O. Francke , A. Valdez , E. Miranda and J. Cruz )], ( 21°09′48.34″N , 98°56′33.86″W ). Municipio Chapulhuacán , 1.5 km of insertion to Pisaflores . 1 ♀ paratype [ AMNH ( 28.vii.1966 ; J. and W. Ivie )], ( 20°33′N , 99°07′12″W ). Municipio Zimapán , 8 km N from Encarnación . San Luís Potosí : 1 ♀ paratype [ AMNH ( 25.vii.1966 ; no collector)], ( 21°14′40.52″N , 98°46′21.28″W ). Municipio Tamazunchale , 1.6 km SW from Tamazunchale . Etymology: From the Latin singularis (unique), in reference to the unique shape of the scutum. Diagnosis: Sexual dimorphism in the shape of scutum remarkable, males with scutum broadly rounded, females subrectangular ( Fig. 18B ). Ornamentation only present on midsection of mesotergal areas III and IV. Spines of the ocularium long, fused at their bases, par- allel, and close to each other ( Fig. 19C ). Sexual length of femur ratio II: 1.38 and IV: 1.37. Dorsoectal apophyses of coxa IV present, sexually dimorphic. Trochanter II with dorsal apophysis in males ( Fig. 61H ). Tibia IV in males curved and slightly swollen in the middle, with conspicuous ventral armature ( Fig. 19A ). Male genitalia: apical margin slightly convex, dentate. Lateral setae cylindrical basally, flattened distally, basal pair shorter than the rest and ventrally displaced. Parastylar setae lateral to follis, basal pair slightly displaced towards follis base. Spiniform projections exposed, noticeably larger than in the other species ( Fig. 20 ). Figure 19. Karos singularis sp. nov. A, legs IV, mesal view. B, habitus, ventral view. C, ocularium, frontal view. Scale bars: A = 2.3 mm, B = 3.5 mm, C = 0.5 mm. The dark lines on (B) indicate the stigmatic area. Figure 20. Karos singularis sp. nov. male genitalia. A, dorsal view. B, ventral view. C, lateral view. White arrows indicate ventral microsetae in (B) and parastylar setae in (C). Description: Male holotype : Measurements: scutum length 3.0, maximum scutum wide 2.9. Legs. I 1.35/ 0.50/1.07/1.40, II 2.50/0.85/2.07/2.05, III: 1.65/0.60/ 1.45/1.75, IV: 2.75/0.85/2.50/2.77. Dorsum . Scutum Ming vase-shaped, but noticeably broad in the middle ( Fig. 18B ). Tubercles of the transversal rows present only in mesotergal areas II–IV, increasing in size posteriorly, area II with few central tubercles; tubercles of area III small. Spines of the ocularium long, fused at the bases, parallel and close to each other ( Fig. 19C ). Lateral clear areas on sides of scutum projected with triangular shape, blunt apically. Lateral clear areas of area V apices and free tergites I and II present, blunt in area V, spiniform in free tergites. Venter. Densely covered by spiniform tubercles, these are larger on coxa IV. Coxa IV only with dorsoectal apophysis, increasing in size distally. Pedipalps. Patella with two mesodistal tubercles. Legs. Legs I and II thinner and less ornate than posterior legs. Femur III curved. Trochanter III globular. Trochanter II with dorsal apophysis ( Fig. 61H ). Ventral armature of femur IV formed by scattered spiniform tubercles. Distal portion of femur IV with noticeable spiniform tubercles. Tibia IV mesally curved, swollen, and with ventral armature ( Fig. 19A ). Tarsal count 4(2):6–7(3):6:6. Male genitalia. Apical margin slightly convex, dentate. Lateral setae with bases cylindrical, flattened apically. Basal pair small and displaced ventrally. Ventral microsetae level with distal pair of lateral setae. Two pairs of parastylar setae lateral to follis, basal pair slightly displaced towards base of follis. Spiniform projections exposed. Lateral margins of ventral plate concave ( Fig. 20 ). Female paratype : Measurements: scutum length 2.7, maximum scutum width 2.2. Similar to male, with the following differences: scutum subrectangular, very different in shape from male; sexual proportion of femora to metatarsi: II 1.38/1.41/1.59/1.32 and IV 1.37/1.29/1.47/ 1.27 ( Figs 18A , 19A ). Femur IV thinner, ventral tubercles of leg IV smaller, tibia IV not curved, dorsoectal apophyses of coxa IV reduced. Tarsal count 4(2):6(3): 6:5/6. Comparisons: Karos singularis sp. nov. is unique among the genus in having noticeable sexual dimorphism in scutum shape, and it is the only species of Karos with dorsal apophysis on trochanter II in males ( Fig. 61H ).