Karos hexasetosus, Cruz-López & Francke, 2015

Cruz-López, Jesús A. & Francke, Oscar F., 2015, Cladistic analysis and taxonomic revision of the genus Karos Goodnight & Goodnight, 1944 (Opiliones, Laniatores, Stygnopsidae), Zoological Journal of the Linnean Society 175 (4), pp. 827-891 : 846-848

KAROS HEXASETOSUS SP. NOV. ( FIGS 12–14 , 58 )

Type material: MEXICO: San Luís Potosí: ♂ holotype, and 1 ♂, 1 ♀ and 1 juvenile paratypes [CNAN- T0726 and CNAN-T0727 (13.ii.2011; O. Francke, A. Valdez, C. Santibáñez, J. Cruz and G. Contreras)], (21°37′48″N, 99°03′38.73″W). Municipio Aquismón, Afueras de la Cueva de El Sol , Mantetzulel .

Etymology: Derived from the Latin hexa (six) and saeta (setae), referring to the presence of six parastylar setae.

Diagnosis: Sexual dimorphism in scutum shape unremarkable. Transversal rows of tubercles on mesotergal areas II – IV complete, central tubercles slightly increasing in size distally ( Fig. 12B ). Spines of the ocularium small. Sexual length of femur ratio II: 1.34 and IV: 1.50 ( Fig. 12A ). Metatarsus II with seven clear annuli in males, five in females. Femur IV slightly curved in females. Dorsoectal apophyses of coxa IV present, small and similar in size in both sexes. Male genitalia: apical margin slightly convex. Lateral setae basally cylindrical, flattened distally, basal pair shorter than the rest, ventrally displaced. Three pairs of parastylar setae. Spiniform projections exposed, relatively large ( Fig. 14 ).

Description: Male holotype: Measurements: scutum length 2.8, maximum scutum width 2.2. Legs. I 1.75/ 0.65/1.15/2.00, II 4.15/1.85/3.45/4.15, III 2.10/0.60/1.70/ 2.20, IV 4.40/1.35/3.85/4.15. Dorsum. Transversal row of tubercles on mesotergal areas complete, increasing in size posteriorly. Median tubercles of area II slightly longer ( Fig. 12C ). Spines of the ocularium small. Lateral clear areas projected in triangular shape, lateral clear areas on apices from area V and free tergites I– III present, spiniform, inconspicuous in free tergite III. Venter. Covered by small spiniform tubercles, with apical setae present. Coxa IV only with dorsoectal apophyses, long. Pedipalps. Patella with a single mesodistal spiniform tubercle. Legs. All legs similar in thickness and ornamentation, covered by small spiniform tubercles. Femora II and IV noticeably elongated ( Figs 12A , 13A ). Patella II elongated. Metatarsus II with seven clear annuli, femur III straight. Tarsal count 4(2):9(3):6:6. Male genitalia. Apical margin convex. Lateral setae cylindrical at the base, distally slightly flattened, basal pair displaced to ventral side. Three pairs of parastylar setae flanking follis, basal pair not protruding beyond follis base. Spiniform projections exposed, conspicuous. Lateral margins of ventral plate slightly concave ( Fig. 14 ). Female paratype: Measurements: scutum length 2.2, maximum scutum width 1.7. With the following differences from the male: scutum slightly rectangular, sexual proportion of femora to metatarsi: II 1.34/1.79/1.54/1.54 and IV 1.50/1.70/1.68/ 1.50 ( Fig. 12A ). Five clear annuli in metatarsus II. Tarsal count 4(2):7–8(3):6:6.

Natural history: The specimens were collected under rocks that were strongly adhered to the soil, inhabiting small hollows in the rocks. Initially they showed thanatosis behaviour, then after a short time they ran away.

Comparisons: This is the only species of Karos with three pairs of parastylar setae, the highest count of clear annuli on metatarsus II, and proportionally long legs.

Figures

Figure 12. Karos hexasetosus sp. nov. A, habitus, dorsal view. B, scutum, dorsal view. C, habitus, lateral view. Scale bars: A = 3.5 mm, B = 2 mm, C = 1 mm.

Figure 13. Karos hexasetosus sp. nov. A legs IV, mesal view. B, habitus, ventral view. C, ocularium, frontal view. Scale bars: A = 3.5 mm, B = 2.0 mm, C = 0.5 mm. The dark lines on (B) indicate the stigmatic area.

Figure 14. Karos hexasetosus 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).

Figure 58. Distribution map of the species of the Karos genus-group, continued. Black circle, Montabunus foliorum; black square, Karos hexasetosus sp. nov.; white square with black outline, Karos monjarazi sp. nov.; black triangles, Potosa dybasi; white triangle with black outline, Potosa reddelli sp. nov.; black crosses, Chapulobunus poblano sp. nov.