Ricstygnus quineti, Kury, Adriano B., 2009

Kury, Adriano B., 2009, A new genus of Stygninae from a relictual rainforest in Ceará, northeastern Brazil (Opiliones, Laniatores, Stygnidae), Zootaxa 2057, pp. 63-68 : 64-67

Ricstygnus quineti sp. nov.

( Figs 1–8 )

Etymology. The species name is a tribute to the zoologist Yves Patric Quinet (Universidade Estadual do Ceará), who has made valuable contributions to our knowledge of Brazilian "brejos de altitude".

Distribution. Brazil, Ceará state, Serra de Baturité, Guaramiranga (860 m 04°16'S – 038°56'W) and Pacoti (850 m, 04°15'S – 038°55'W).

Type material. Brazil, Ceará state: 3 holotype 1 Ƥ paratype ( MNRJ 02112; 3 genitalia on stub BZ), Serra de Baturité, Guaramiranga (Parque das Trilhas) 860 m 04°16'S – 038°56'W, 23.vii.2002, Y. Quinet leg.; 2 Ƥ paratypes ( MNRJ 02125), same locality, Winkler extraction, 23.vii.2002, Y. Quinet leg.; 1 3 2 Ƥ paratypes ( MNRJ 2162), same data, 25.vii.2002; 2 Ƥ paratypes ( MNRJ 02126), Pacoti, Serra de Baturité, 850 m, 04°15'S – 038°55'W, Winkler extraction, 15.iii.2001, Y. Quinet leg.; 1 juv. paratype ( MNRJ 02127), same locality, Winkler extraction, 17.iii.2001, Y. Quinet leg.

Diagnosis. As for the genus.

Description of male holotype.

Measurements. CL 1.6, AL 1.5, CW 2.4, AW 2.6. See Table 1 for measurements of appendages.

Tr Fe Pa Ti Mt Ta claw Pedipalpus 0.6 2.7 1.7 1.3 – 1.0 0.7 Leg I 0.6 2.1 0.8 1.6 2.1 1.1 – Leg II 0.5 2.9 1.0 2.2 2.5 2.7 – Leg III 0.6 2.3 0.8 1.7 2.7 1.6 – Leg IV 0.7 3.0 1.1 2.1 3.4 1.9 –

Dorsum ( Figs 1–2 ). Dorsal scutum subtrapezoid, with 2 constrictions at eye-line and area II. Posterior margin sinuous and convex in middle. Stout interocular spiniform apophysis near anterior margin. Cheliceral sockets narrow and shallow. Eyes placed far from each other and far from anterior margin of carapace. Carapace wide V-shaped, its boundaries inserting deeply into area I until touching groove II. Four welldefined mesotergal areas, area I bisected into two subtriangular halves by an extension of carapace. Areas III to posterior margin each with a pair of paramedian acuminate tubercles increasing in size posteriorly. Free tergites each with a row of granules. Free tergite I with a pair of robust, acuminate, spiniform apophyses that are by far the stoutest of all on dorsum.

Chelicera ( Figs 1–2 ). Basichelicerite not particularly robust or elongate, bulla attenuate, armed with a few dorsal tubercles. Cheliceral hand only moderately swollen.

Pedipalpus ( Figs 1–3 ). Coxa enlarged, stout, truncate-conical, densely granular. Trochanter short, with dorsal mound armed with huge frontward pointed spine. Femur sinuous, a little longer than peltidium, thickening distally, entirely unarmed. Patella resembles a shorter version of femur, with distal thickening steeper. Tibia and tarsus forming a subchela with femur. Tibia heavily bent dorsally, ventro-ectal face with 4 and ventro-mesal face with 4 thin setiferous tubercles. Tarsus with 6 thin setiferous tubercles on each side.

Legs. Trochanter II and IV each with a robust, dorso-anterior, spiniform apophysis ( Fig 2 ). Femora I–IV each with a ventro-prolateral and a ventro-retrolateral parallel row of acuminate tubercles, vestigial on I, much larger on III and IV. Femora III–IV incrassate and with supplementary prolateral row of tubercles. Patella IV densely granular, with two larger dorso-apical tubercles. Tibia IV with 3 parallel rows of acuminate tubercles in same positions as on femora. Tarsal claws of legs III–IV unpectinate, subparallel. Scopula very sparse, tarsal process present. Tarsal counts: 6(3)/15(3)/6/7.

Color. Body and appendages dark orange brown, with sparse darker reticule. Noticeably darker are: free tergites and sternites, lateral and posterior borders of dorsal scutum. Pedipalps and chelicerae a little lighter. No spots or stripes.

Genitalia ( Figs 4–8 ). Pars distalis of truncus sharply separated from pars basalis by a ventro-lateral articular fold ring ( Figs 4–6 ). Ventral plate (VP) clearly pyriform in ventral/dorsal view ( Figs 4–5 ). Thick subrectangular in lateral view ( Fig. 6 ). Ventral plate dorso-basally with a large subcircular hollow containing a multiply folded haematodocha ( Fig. 5 ). Apical border of VP truncate, roofed, with a pair of straight lateral prongs directed dorsally ( Figs 6–7 ). VP also with a ventro-distal mat of microvilosities ( Figs 4, 7 ). VP with four groups of macrosetae: 3 pairs of huge, cornute distally flattened macrosetae inserted dorso-laterally ( Figs 5, 7 ); 3 pairs of somewhat smaller, straight, latero-medial spines, clearly transverse, forming a 90° angle to main axis of penis; 1 pair of short, stumpy, dorso-medial spines ( Figs 5 ); and 2 pairs of very small, acuminate, ventro-lateral tubercles adjacent to mat and deeply buried in sockets ( Fig. 6 ). Glans sac short, not rigid ( Fig. 5 ). Glans dorsal process straight, tapering, a little shorter than stylus. Stylus strongly bent, apex only a little expanded apically ( Fig. 8 ).

Variation. The only other male present in the type series is bleached by fixation. It is a little stouter than the holotype and the armature of legs III–IV more robust. Tarsalia of males (n = 2) 6–7(3)/15–16(3)/6/7.

Sexual dimorphism. Females with chelicerae clearly smaller, femora III–IV unarmed and not incrassate. Range of tarsalia in females (n = 7) 6–7(3)/13–15(3)/6/7.

Figures

FIGURES 1 – 3. Ricstygnus quineti sp. nov., male holotype from Guaramiranga, Ceará, Brazil. 1, habitus, dorsal view. 2, habitus, lateral view. 3, femur – tarsus of right pedipalpus, lateral view (same scale as fig. 2). Scale bars = 1 mm.

FIGURES 4 – 8. Ricstygnus quineti sp. nov., penis, distal part, male holotype from Guaramiranga, Ceará, Brazil. 4, ventral view. 5, dorsal view, 6, lateral view. 7, detail of hood of ventral plate, dorso-lateral view. 8, glans, lateral view.