Eusarcus alpinus, Hara & Pinto-Da-Rocha, 2010

Hara, Marcos Ryotaro & Pinto-Da-Rocha, Ricardo, 2010, Systematic review and cladistic analysis of the genus Eusarcus Perty 1833 (Arachnida, Opiliones, Gonyleptidae) 2698, Zootaxa 2698, pp. 1-136 : 29-31

Eusarcus alpinus sp. n.

( Figs. 4, 43A,B, 49A)

Type material: BRAZIL. Rio de Janeiro: Santa Maria Madalena (P.E. do Desengano), A.B. Kury, M. Baptista, A.P.L. Giupponi leg., 23–25.iii.1998, ma holotype & 2 fe paratypes ( MNRJ 5719 ); idem, 1 ma & 1 fe paratypes ( MZSP 28665 ); Teresópolis (Colônia Alpina), E.A. Goeldi leg., without date, 3 ma, 3 beta male, 2 fe & 2 im paratypes ( ZMUC) .

Diagnosis: E. alpinus resembles E. incus , E. pusillus , E. nigrimaculatus , E. acrophthalmus , E. didactylus and E. geometricus because of the cylindrical prolateral median process on male trochanter IV and generally large body size, and can be distinguished by: The ocularium with 2 large tubercles, the rectangular projection on the retrolateral margin of the prolateral apical apophysis of coxa IV and the shape of cylindrical prolateral median process of male trochanter IV: Prolateral edge of apex inflated, blunt; retrolateral edge of apex with blunt, upwards pointing finger-shaped projection; basally with a small, blunt, slightly conical apophysis. Penis without ventral process of glans (unusual within the genus); stylus curved ventrad, without trichomes and angular medio-ventral projection; ventral plate elliptic; trunk covering base of glans dorsoventrally.

Etymology: The species name, an adjective, refers to the type locality, Colônia Alpina, a Swiss colony founded by Emil August Göldi. He was a remarkable and important Swiss researcher who helped to promote natural history in Brazil.

Description: Male (holotype): Dorsum ( Fig. 4A,B): Measurements: SL 4.80; SMW 4.30; femur I 2.15; II 4.20; III 3.20; IV 3.80. Median paracheliceral projection of similar-size as PAM. Ocularium far from anterior scutal margin; with 2 large tubercles and 12 smaller ones. Carapace with 35 scattered tubercles. Scutal area I with 43 scattered tubercles on each side; II with 91; III with 100 and a median spine directed backwards, almost straight, curved only apically, surpassing posterior margin of dorsal scutum; IV with 50 tubercles. Posterior margin of dorsal scutum with 31 scattered tubercles. Free tergites I–III with an irregular row of 22, 18, 18 tubercles, respectively. Anal operculum with 39 tubercles.

Venter: Coxa I with 33–34 tubercles, median and distal ones largest; II–III with 56–58, 60–69 tubercles increasing in size distally, respectively; IV densely and irregularly tuberculate.

Chelicera: Segment I with 2 tubercles.

Pedipalpus: Trochanter dorsally inflated, with 4 tubercles. Femur dorsally with 4 aligned tubercles, 5 apical small ones; ventrally with 1 large pointed basal tubercle, 2 small scattered tubercles. Tibial setation: Prolateral IiIi, retrolateral iiIi/IiIi. Tarsal setation: Prolateral IIi, retrolateral IiIi/Iii.

Legs ( Fig. 4C–H): Coxa II with 5–7 tubercles on retrolateral margin; IV densely tuberculate, with 1 oblique prolateral apical apophysis, this conical, long, blunt, curved posteriad and slightly ventrad, with 1 rectangular projection on retrolateral margin. Trochanters I–IV with scattered tubercles; I–III with large retrolateral tubercle; I–II with 1 large ventro-basal tubercle; IV prolaterally with 1 cylindrical and flattened median process, this prolateral edge of apex inflated, blunt; retrolateral edge of apex with blunt, upwards pointing finger-shaped projection; basally with a small, blunt, slightly conical apophysis; retrolaterally with 1 large pointed subasal tubercle, 1 median and 1 apical large blunt tubercle; 1 large pointed ventro-apical tubercle. Femur I with reduced PDS, RDS; II–III with reduced PDS, large RDS; III sinuous, ventrally with 2 rows of tubercles increasing in size distally, prolateral ones enlarged, pointed, 1 small, blunt prolateral apical spine; IV sinuous, with medium PDS, large RDS; a retrolateral row of enlarged, slightly pointed tubercles; ventrally with two irregular rows of tubercles increasing in size distally, prolateral ones becoming pointed (5 large), 2 apical spines. Patellae III–IV with enlarged, slightly pointed ventral tubercles. Tibia III ventrally with 2 rows of pointed tubercles increasing in size subapically, retrolateral ones largest (3–4 large); IV ventrally with 2 rows of tubercles increasing in size distally, becoming pointed, 2 apical spines. Metatarsi III–IV with tubercles decreasing in size and number distally. Tarsal segmentation: 6, 8–9, 6, 6.

Penis ( Fig. 43A,B): Stylus smooth, apex swollen, curved ventrad; without trichomes and angular medioventral projection. Ventral process of glans absent. Ventral plate elliptic; with 3 pairs of short distal setae; 1 pair of short, straight, thick median setae; 4 pairs of long, straight basal setae, basalmost pair very close to trunk of penis. Trunk covering base of glans dorsoventrally.

Coloration: Brown; dark brown on body margin, spines, apophyses and patellae, basal and apical areas of femora and tibiae. Light brown on metatarsi and tarsi.

Female (paratype; MNRJ 5719): Dorsum: Measurements: SL 4.95; SMW 3.80 femur I 2.05; II 4.00; III 3.00; IV 3.70. Free tergites I–III with rows of 15 and 22, 12 and 24, 12 and 16 tubercles, respectively. Pedipalpus: Tibial setation: Prolateral and retrolateral IiIi. Tarsal setation: Prolateral IIi, retrolateral IiIi. Legs: Coxa II with 1 prolateral tubercle, 4 retrolateral; IV densely tuberculate, with 1 oblique prolateral apical apophysis, this conical, short, pointed, curved backwards, surpassing posterior margin of this segment. Trochanter IV with scattered tubercles, retrolaterally with 1 large median tubercle, 1 short, blunt apical apophysis. Femur I ventrally with 2 rows of slightly enlarged tubercles; III ventrally with 2 rows of tubercles increasing in size distally, prolateral ones enlarged, 1 short, blunt prolateral apical spine, 1 large retrolateral apical tubercle; IV ventrally with two irregular rows of tubercles (prolateral ones enlarged) increasing in size distally, 1 blunt prolateral apical spine, 1 large retrolateral apical tubercle. Tibiae I, IV with two ventral rows of slightly enlarged tubercles, without spines; III with rows of similar-sized tubercles. Tarsal segmentation: 6, 8, 6, 6.

Variation in males (n=5): Measurements: SL 4.05–4.80; SMW 3.70–4.00; femur I 1.80–2.15; II 3.80– 4.20; III 2.90–3.60; IV 3.50–3.80. Median paracheliceral projection smaller or similar-sized as PAM. Pedipalpus: Tibial setation: Prolateral IiIi/iii, retrolateral IiIii/iiIi/IiIi/IIi. Tarsal setation: Prolateral IIi/iIi, retrolateral IiIi/Iii. Trochanter III with or without large ventro-basal tubercle; IV with 1–2 large retrolateral apical tubercles. Femora I–II ventrally with 2 rows of slightly enlarged or similar-sized tubercles; I with reduced or small PDS, RDS; II–III with reduced or small PDS, medium or large RDS; III with or without 1 large retrolateral ventro-apical tubercle. Tibia I with 2 rows of similar-sized tubercles or increasing in size distally; IV with or without 1 retrolateral apical spine. The beta male form has its coxa IV reaching grooves III–IV and its prolateral median apophysis of trochanter IV conical instead of cylindrical and flattened.

Variation in females (n=7): Measurements: SL 4.50–4.95; SMW 3.00–3.80; femur I 1.80–2.05; II 3.50– 4.00; III 2.80–3.00; IV 3.50–3.70. Pedipalpus: Tibial setation: Prolateral IiiIi/IiIi/IIi, retrolateral IiIii/IiIi/IIi. Trochanter III with or without large ventro-basal tubercle. Femur I with reduced or small RDS; II with medium or large RDS; III with reduced or small PDS, medium or large RDS; IV with medium or large RDS. Tibia I with two ventral rows of slightly enlarged or similar-sized tubercles. Tarsal segmentation: 6, 7–10, 6, 6.

Type locality: Brazil, Rio de Janeiro, Santa Maria Madalena, Parque Estadual do Desengano .

Geographical distribution ( Fig. 49A): Brazil. Rio de Janeiro.