Nerudiella cautin, Porto & Derkarabetian & Giribet & Pérez-González, 2024

Porto, Willians, Derkarabetian, Shahan, Giribet, Gonzalo & Pérez-González, Abel, 2024, Systematic revision of the South American “ Nuncia ” (Opiliones, Laniatores, Triaenonychidae), ZooKeys 1207, pp. 1-149 : 1-149

Nerudiella cautin sp. nov.

Figs 86 , 87 , 88 , 89 , 90 , 91

Material examined.

Holotype. ♂ Chile. Región de Los Lagos, Llanquihue, 13 km W Río Negro. Berlese . N. Platnick, R. Schuh coll., coll, 24. I. 1986 ( AMNH) . Paratypes. Chile. Palena, Vicinity of Chaitén , 0–100 m. Berlese. N. Platnick, R. Schuh 5–7. XII. 1981 2 ♂ 2 ♀ 7 imm. ( AMNH) . Same data, 1 ♀ 3 imm. ( AMNH) . Los Lagos, Palena, 25–27 km North Chaitén , 40 m. P. Goloboff, R. Schuh 17. I. 1986 2 ♂ ( AMNH) . Coihaique, 10 km N Reserva Nacional Coyhaique . S. Peck, J. Peck. 22. I. 1985 1 ♀ ( FMNH) . Aysén, 30 km N Puerto Cisnes . E. Maury. 09. XII. 1986 ( MACN) .

Etymology.

The specific epithet refers to the type locality of the species, the province of Cautín, located in the southern zone of Chile. Noun in apposition.

Diagnosis.

The sharp tubercles on the dorsal scutum surface distinguish this species from others its congeners, particularly when observed from a dorsal view. The genitalia shows a unique U-shaped capsula externa (Fig. 91 D ).

Distribution.

Chile: Bío-Bío, Araucanía, Los Ríos, and Los Lagos Regions (Fig. 4 F ).

Description of male holotype.

Total length 4.17, carapace length 1.26, dorsal scutum length 2.64, carapace max. width 1.51, mesotergum max. width 2.06. Appendage measurements: Pedipalps. Trochanter length 0.35, femora length 1.05, patella length 0.58, tibia length 0.79, tarsus length 0.73. Leg I: trochanter (tr) 0.22, femora (fe) 0.83, patella (pa) 0.48, tibia (ti) 0.67, metatarsus (mt) 0.80, tarsus (ta) 0.71. II: tr 0.23, fe 1.17, pa 0.64, ti 0.89, mt 1.03, ta 1.33. III: NA. IV: tr 0.35, fe 1.15, pa 0.64, ti 0.96, mt 1.22, ta 0.98.

Dorsum (Fig. 86 , 87 ). Dorsal scutum microgranulate, without clear delimitation of areas. Area I characterized by a row of three setae, while areas II – III display a row of six low, broad, arch-shaped setiferous tubercles. Area IV and posterior margin with a row of low, broad setiferous tubercles. Free tergites with a row of low, broad setiferous tubercles.

Chelicerae (Fig. 88 A, B ). Segment I with a small tubercle on the dorso-distal surface. Segment II with a mesal tubercle and bearing few setae.

Pedipalps (Fig. 88 C, D ). Trochanter with a small dorsal and ectal tubercle. Femora with two ventroproximal tubercles with subdistal setae, four distal setiferous granules, and three dorsoproximal tubercles with subdistal setae. Mesal surface of the femora with two rows of setiferous granules. Patella with ventral setiferous granules. Tibia with three ectal and two mesal spines with subdistal setae, the ventral surface adorned with small setiferous granules. Tarsus with three mesal and ectal spines with subdistal setae, with a few setae and granules.

Legs (Fig. 89 ). Coxae I – II with setiferous tubercles, with the longest distal tubercle bearing a subdistal seta. Coxae III and IV with microgranulation only, lacking setiferous tubercles. With four bridges between legs II and III, five or six bridges between III and IV, and four bridges between leg IV and the opisthosoma, the distal bridge longer than the others. Spiracles not obstructed by bridges. The smooth surface occupies ~ 1 / 3 of leg II, with two small tubercles and two rounded tubercles present. In leg III, the smooth area covers ~ ¾ of the surface, while in leg IV, it occupies <1 / 3 of the surface. Sternum arrow-shaped. Legs smooth, with sparse setae. Tarsal count: 4–7 – 4 – 4.

Penis (Figs 90 , 91 ). Pars distalis with large ventral plate bearing a cleft dividing the plate into two lamellae. Each lamella with three pointed macrosetae on the ventral surface and one macroseta on the dorsal surface. Capsula externa covering dorsal and lateral surfaces, with a long cleft dividing capsula externa into two parts; with a dorsolateral plate attached to the pars basalis. Capsula interna longer than capsula externa, partially covering the ventral plate, the apical region of the capsula interna thin and sharp, the stylus not visible in its apical portion.

Female. Similar to males, but with a noticeable shorter pedipalpal femora.

Female measurements. Total length 2.2, carapace length 1.00, dorsal scutum length 2.1, carapace max. width 1.3, mesotergum max. width 2.0. Appendage measurements: Pedipalps. Trochanter length 0.21, femora length 0.85, patella length 0.50, tibia length 0.50, tarsus length 0.63. Leg I: trochanter (tr) 0.22, femora (fe) 0.87, patella (pa) 0.47, tibia (ti) 0.66, metatarsus (mt) 0.76, tarsus (ta) 0.65. II: tr 0.25, fe 1.10, pa 0.60, ti 0.89, mt 0.99, ta 1.21. III: tr 0.25, fe 0.75, pa 0.36, ti 0.58, mt 0.61, ta 0.67, IV: tr 0.33, fe 1.05, pa 0.66, ti 0.89, mt 1.09, ta 0.78. Tarsal count 3–6 – 4 – 4.

Figures

Figure 4. Maps showing the distribution of the species used in this work. South America (Chile and western Argentina inset). Chile in green, Argentina / South America in grey. Terrestrial ecoregions (following Olson et al. 2001) highlighted in yellow (Chilean Matorral) and orange (Valdivian temperate forests).

Figure 86. Nerudiella cautin sp. nov. habitus, male A dorsal view C lateral view E ventral view. Female B dorsal view D lateral view F ventral view. Scale bars: 1 mm.

Figure 87. Nerudiella cautin sp. nov. male, SEM images of habitus A dorsal view B lateral view C, D ventral view. Scale bars: 500 µm.

Figure 88. Nerudiella cautin sp. nov. chelicerae: mesal A ectal B pedipalps: mesal C ectal D. Scale bars: 200 µm (A, B); 500 µm (C, D).

Figure 89. Nerudiella cautin sp. nov. legs I A II B III C IV D. Scale bars: 500 µm.

Figure 90. Nerudiella cautin sp. nov. penis: ventral A, B apical C lateral D, E dorsal F, G. Scale bars: 200 µm (A, D, F); 50 µm (B, C, E, G).

Figure 91. Nerudiella cautin sp. nov. penis: ventral A apical B lateral C dorsal D. Colors: ventral plate (yellow), capsula externa (blue), capsula interna (red). Scale bars: 50 µm.