Eusarcus bifidus Roewer

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 : 37-39

Eusarcus bifidus Roewer

( Figs. 7, 47E,F, 49B)

Eusarcus bifidus Roewer 1929: 196 (key), 199, fig. 6; Mello-Leitão 1932: 156 (key), 161 (rdesc); 1940: 6 (key); B. Soares 1944e: 201 (cit); Mello-Leitão 1945: 153 (cat), 156 (key), fig. 9; H. Soares 1945: 217 (cit); Soares & Soares 1954b: 259 (cat); H. Soares 1966b: 109 (syst, diag); Acosta 1996b: 216 (cat); Kury 2003a: 168 (cat); (ma holotype; “ Brasilien, Matto Grosso; SMF RII/955.36”; examined).

Goyazia bifida: Piza 1940b: 313 , fig. 2 (by implic).

Material examined: BRAZIL. Old Mato Grosso: Without locality, name of collector and date, ma holotype of E. bifidus ( SMF, RII/955.36 ) . Mato Grosso do Sul: Corumbá ( Passo da Lontra ), A.D. Brescovit leg., vi.1998, 1 ma ( IBSP 1177 ) ; idem ( Serra de Urucum ), K. Lenko & A. Carvalho leg., 25–30.xi.1960, 2 ma & 3 fe ( MNRJ 16173 ) ; Dois Irmãos do Buriti ( Piraputanga , 20°27’S 50°30’W), A.D. Brescovit et al. leg., 31.vi– 6.vii.1999, 1 ma ( IBSP 1550 ) ; idem, 2 fe ( IBSP 1551 ) .

Diagnosis: E. bifidus resembles E. caparaoensis + and E. manero +, which have a conical, short, blunt prolateral basal apophysis on male trochanter IV, and can be distinguished by: The presence of PAM; ocularium with two spines or a bifid apophysis; median spine of scutal area III short; trochanter IV with prolateral apical apophysis prolaterally inserted; femur IV with a prolateral row of slightly pointed, enlarged tubercles; a retrolateral row with pointed tubercles decreasing in size distally; ventrally with 2 rows of tubercles increasing in size distally, prolateral ones enlarged, 2 apical spines.

Redescription: Male (holotype): Dorsum ( Fig. 7A,B): Measurements: SL 3.65; SMW 3.45; femur I 1.90; II 3.70; III 2.60; IV 3.35. Median paracheliceral projection of similar-size as PAM. Anterior margin of prosoma with 1 large tubercle on right corner. Ocularium next to anterior scutal margin; high, with 1 bifid apophysis, 6 tubercles. Carapace with 24 scattered tubercles. Scutal area I with 7–12 scattered tubercles on each side; II with 31; III with 21 and a median spine short, not surpassing groove IV; IV with 27 tubercles. Posterior margin of dorsal scutum and free tergites I–III with a row of 20, 16, 16, 12 tubercles, respectively. Anal operculum with 32 tubercles.

Venter: Coxa I with 25–29 tubercles, median and distal ones largest; II with 39–40, distal ones largest; III– IV irregularly tuberculate.

Chelicera: Segment I with 3 tubercles.

Pedipalpus: Trochanter dorsally inflated, with 3 tubercles. Femur dorsally with 7 aligned tubercles, 1 mesal; ventrally with 1 large pointed basal tubercle, 3–5 small aligned tubercles. Tibial setation: Prolateral IIi/ IiIi, retrolateral IiIi. Tarsal setation: Prolateral IIi, retrolateral IiIi.

Legs ( Fig. 7C–J): Coxa II with 3 tubercles on retrolateral margin; IV densely tuberculate, with 1 almost transversal prolateral apical apophysis, this conical, long, blunt, curved posteriad and ventrad, slightly swollen on median retrolateral face. Trochanters I–IV with scattered tubercles; I–II with 1 large ventro-basal tubercle; II with 1 large retrolateral apical tubercle; IV prolaterally with 1 basal apophysis, this conical, short, blunt, dorsally angular; 1 oblique apical apophysis, this short, blunt, with 1 large tubercle on the base; retrolaterally with 1 large median tubercle, 1 oblique apical apophysis, this conical, short, blunt. Femur I with reduced PDS, RDS; ventrally with 2 rows of slightly enlarged tubercles; II–III with small PDS, RDS; III sinuous, ventrally with 2 rows of tubercles increasing in size distally, 2 apical spines, prolateral one largest; IV sinuous, with tubercles decreasing in size distally, medium PDS, RDS; prolateral row of enlarged, slightly pointed tubercles; a retrolateral row with pointed tubercles decreasing in size distally; ventrally with 2 rows of tubercles increasing in size distally, prolateral ones enlarged, 2 apical spines. Tibia I ventrally with 2 rows of slightly enlarged tubercles; III with a retrolateral row of pointed tubercles increasing in size to the middle; with 2 ventral rows of pointed tubercles, increasing in size subapically, retrolateral ones enlarged; IV ventrally with 2 rows of tubercles increasing in size distally, retrolateral ones slightly enlarged, 2 apical spines. Metatarsus I with 2 ventro-apical setae. Tarsal segmentation: 6, 8, 6, 6.

Penis ( Fig. 47E,F): Stylus with medio-ventral trichomes, apex slightly swollen; with angular medioventral projection. Ventral process of glans curved, apex with flabelliform projection. Ventral plate with concave sides; with 3 pairs of long, slightly curved distal setae; 1 pair of ventral subapical setae, this small, short, straight; 1 pair of short, straight median setae; 4–5 pairs of straight basal setae.

Coloration: Light brown on most parts of the body, distal portion of femur IV and tibia IV, patella, metatarsus and tarsus. Brown on the body edges, legs and apophyses.

Female (IBSP 1551): Dorsum: Measurements: SL 3.10; SMW 2.80; femur I 1.40; II 2.30; III 1.90; IV 2.30. Anterior margin of prosoma with 1 tubercle on each corner. Pedipalpus: Tibial setation: Prolateral IiIi, retrolateral IiIi/iIi. Legs: Coxa IV densely tuberculate, with 1 oblique prolateral apical apophysis, this conical, short, pointed. Trochanter IV with scattered tubercles, with 1 large retrolateral subapical tubercle. Femur III ventrally with a prolateral row of tubercles increasing in size distally, 1 large apical tubercle; IV with dorsal, prolateral and retrolateral rows of similar-sized tubercles, with small RDS; ventrally with a prolateral row of tubercles increasing in size distally, 1 large pointed prolateral apical tubercle. Tibiae I, III–IV with rows of similar-sized tubercles. Tarsal segmentation: 5, 7, 6, 6.

Variation in males (n=4): Measurements: SL 3.45–3.65; SMW 3.00–3.45; femur I 1.50–1.90; II 2.70– 3.70; III 2.15–2.60; IV 2.60–3.35. Ocularium with 2 spines or a bifid apophysis. Pedipalpus: Tibial setation: Prolateral IiiIi/IiIi/IIi. Femur II with reduced or small PDS; III with small or medium RDS. Tarsal segmentation: 5–6, 7–8, 6, 6.

Variation in females (n=6): Measurements: SL 3.10–3.40; SMW 2.80–2.90; femur I 1.40–1.60; II 2.30– 3.00; III 1.80–2.20; IV 2.30–2.85. Pedipalpus: Tibial setation: Retrolateral IiIi/IIi. Femur II with reduced or small PDS, RDS; III with reduced or small PDS, small RDS; IV with small or medium PDS, RDS. Tarsal segmentation: 5–6, 7–8, 6, 6.

Type locality: Brazil, old Mato Grosso (when E. bifidus was described, this state was not yet divided into Mato Grosso and Mato Grosso do Sul) .

Geographical distribution ( Fig. 49B): Brazil. Mato Grosso or Mato Grosso do Sul.