Karos singularis, 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 : 850-852

publication ID

https://doi.org/ 10.1111/zoj.12299

persistent identifier

https://treatment.plazi.org/id/03CA87F9-A242-FFB5-FE88-F9E7C7DEFF36

treatment provided by

Felipe

scientific name

Karos singularis
status

sp. nov.

KAROS SINGULARIS View in CoL SP. NOV.

( FIGS 18–20 View Figure 18 View Figure 19 View Figure 20 , 59 View Figure 59 , 65F View Figure 65 , 61B, H View Figure 61 , 62C View Figure 62 , 64C View Figure 64 )

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 GoogleMaps . 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 GoogleMaps . 1 ♀ paratype [ AMNH (28.vii.1966; J. and W. Ivie)], (20°33′N, 99°07′12″W). Municipio Zimapán, 8 km N from Encarnación GoogleMaps . 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 GoogleMaps .

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 View Figure 18 ). 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 View Figure 19 ). 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 View Figure 61 ). Tibia IV in males curved and slightly swollen in the middle, with conspicuous ventral armature ( Fig. 19A View Figure 19 ). 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 View Figure 20 ).

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 View Figure 18 ). 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 View Figure 19 ). 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 View Figure 61 ). 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 View Figure 19 ). 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 View Figure 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 View Figure 18 , 19A View Figure 19 ). 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 View Figure 61 ).

R

Departamento de Geologia, Universidad de Chile

AMNH

American Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Opiliones

Family

Stygnopsidae

Genus

Karos

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