Thrasychiroides ybytyra, Pinto-Da-Rocha, Ricardo, Bragagnolo, Cibele & Tourinho, Ana Lúcia, 2014

Pinto-Da-Rocha, Ricardo, Bragagnolo, Cibele & Tourinho, Ana Lúcia, 2014, Three new species of Thrasychiroides Soares & Soares, 1947 from Brazilian Mountains (Opiliones, Eupnoi, Neopilionidae), Zootaxa 3869 (4), pp. 469-482 : 475-477

Thrasychiroides ybytyra sp. nov.

( Figs 1 E–F,4A–C; 5J–L; 6G–H)

Type material. Holotype: ♂ from Brejo da Lapa (22º21’45”S, 44º44’06”W, 2200 m.a.s.l.), Parque Nacional do Itatiaia, Itamonte, State of Minas Gerais, Brazil, 5–6.II.1997, A.B. Kury, R. Pinto-da-Rocha & L.A.M. Mestre leg. ( MZSP 25685). Paratypes: same data as holotype, road to Vale dos Lírios (22º21’42”S, 44º42’24”W, 2400 m.a.s.l.), 4.II.1997., 2 ♂ ( MZSP 21256).

Etymology. Ybytyra is a noun from the Brazilian Indian Tupy language meaning “mountain”, indicating the high altitude of the type locality.

Distribution. Known from type locality. One specimen was photographed in a nearby locality Delfim Moreira, in 1.XI.2004 by the first author.

Diagnosis. Ocularium pearl-white with a darkish contour surrounding eyes and with eleven small dorsal setae. Pedipalpal claws with 19 teeth. Chelicerae massive, second segment very inflated and covered with setae, sometimes only on dorsal surface, each finger with one basal very large tooth followed by many smaller teeth. Penis with posterior portion of glans larger than anterior part, dorsal shoulders with acuminate laterals, paired and long bifid setae on dorso-lateral glans. Ventral arms slender and elongated, reaching the distal part of glans. Tips pointed and without apical modification. Stylus with apically sharp-pointed spine curved in “S” with distal third directed to penial base ( Fig. 6 G–H).

Description of males (holotype). Measurements: body length: 3.76; prosoma length: 1.08; prosoma width: 2.44; chelicerae: segment I length: 1.56, segment II: 3.36.

Coloration ( Figs 4 A–C). Dorsum coloration a variety or shades of chestnut with several pearl-like, white, large spots and stripes covering most of the lateral third of the body and small maculations spread on the carapace. Carapace with shades of chestnut, median third of dorsal scutum beige, ocularium pearl-like white with a darkish contour line (ring) surrounding eyes, basal segment of chelicerae beige, other segments with brown shades of chestnut, legs beige with cylindrical-like darker areas on subbasal and subdistal femora, patella, and tibia, trochanters with lateral chestnuts maculations. Pedipalps, ventral trochanter, femora, patella and tibia with chestnuts maculations. Coxae and genital operculum beige with darker chestnuts maculations. Free tergites varying from chestnuts and brownish with median pearl-like white spots, anal operculum pearl like white. Ventral color mostly beige. Only free sternites are chestnuts with white luminous rounded maculations.

Body and appendices ( Figs 1 E–F; 4A–C). Ocularium with eleven small setae distributed dorsally. Small setae spread on dorsal and ventral surface, genital operculum, coxae, pedipalps and chelicerae. Pedipalpal claws with 19 teeth that increase in size towards tip of claw. Pedipalp tuft with setae on the inner face of the femora, a line of setae surrounding the contour of the patella. Patella and tibia with a dorsal and a lateral line lacking setae ( Figs 1 E; 4C). Chelicerae massive, second segment very inflated and covered with setae, in some specimens only on dorsal surface. Each finger with one basal very large tooth followed by many smaller teeth. Tibia of legs II with three apical pseudo-articulations in one specimen.

Penis ( Fig. 5 J–L). Posterior with posterior portion of glans three times larger than the anterior, base concave, shoulders with acuminate laterals forming spines, a pair of long, bifid setae on dorso-lateral glans. Ventral arms slender and elongated reaching the distal part of glans, each branch simple and pointed, without apical ornamentation. Stylus with apical spine curved in “S” with distal third directed towards the penial base ( Fig. 6 G–H).

Biotope. The three specimens were collected at “Brejo da Lapa” (about 22 º21’S, 44 º42’W) at altitudes of 2200 and 2400 m.a.s.l. in Parque Nacional do Itatiaia, State of Minas Gerais, Brazil. The vegetation is Montane Atlantic Rain Forest, which occurs from 1,100 up to 2,700 m.a.s.l ( Santos 2000). The trees are shorter and the average temperature is lower than at the base of the mountain. The high-altitude forests are very humid and are frequently covered in dense mists.

Figures

FIGURE 1. Dorsal and lateral views of the holotypes of the new Thrasychiroides species. A – B. T. moporanga sp. nov., dorsal and lateral view, respectively; C – D. T. toryba sp. nov., dorsal and lateral view, respectively; E – F. T. ybytyra sp. nov., dorsal and lateral view, respectively. Scale bars = 0.5 mm.

FIGURE 4. Photographs of the male holotype of Thrasychiroides ybytyra sp. nov. A. dorsal view; B. lateral view; C. chelicera and pedipalp details. Scale bars = 1 mm.

FIGURE 5. Penes of Thrasychiroides species. A – C. T. brasilicus, A. dorsal view; B. lateral view; C. ventral view. D – F. T. moporanga sp. nov., D. dorsal view; E. lateral view; F. ventral view. G – I. T. toryba sp. nov., G. dorsal view; H. lateral view; I. ventral view. J – L. T. ybytyra sp. nov., J. dorsal view; K. lateral view; L. ventral view. Scale bars = 0.05 mm. Labels. 1 = stylus; 2 = glans; 3 = arms; 4 = shaft; 5 = spine on shoulder.

FIGURE 6. Tips of penial glans of the holotypes of Thrasychiroides species. A – B. T. brasilicus.. C – D. T. moporanga sp. nov. E – F. T. toryba sp. nov. G – H. T. ybytyra sp. nov. Upper row: ventral view; Bottom row: dorsal view. Scale bars = 0.05 mm.