Eusarcus acrophthalmus, 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 : 23-26

Eusarcus acrophthalmus sp. n.

( Figs. 2, 42E,F, 49A)

Eusarcus hastatus : [misid] Roewer 1913: fig. 32; 1923: fig. 523; Mello-Leitão 1932: fig. 84. Type material: BRAZIL. Without locality, name of collector and date, 1 fe paratype (SMF 765); Bahia: Ilhéus (Parataquicé), without name of collector and date, ma holotype, 1 ma, 1 fe paratypes & 2 im (MNRJ 5244); 1 ma & 1 fe paratype (MZSP 28664).

Diagnosis: E. acrophthalmus resembles E. incus , E. pusillus , E. nigrimaculatus , E. alpinus , E. didactylus and E. geometricus because of the cylindrical prolateral median process on the male trochanter IV and generally large body size, and it and can be distinguished by: A high ocularium; dorsal scutum densely tuberculate; irregular projections on retrolateral margin of prolateral apical apophysis of coxa IV, and by the shape of the cylindrical prolateral median process of the male trochanter IV: Distally blunt and basally with a small, blunt, conical apophysis. Unlike in E. alpinus +, the penis of E. acrophthalmus has a ventral process on its glans.

Etymology: From the Greek “acro” = high and “ophthalmos” = eye, in reference to the high ocularium. Noun in apposition.

Description: Male (holotype; MNRJ 5244): Dorsum ( Fig. 2A,B): Measurements: SL 6.00; SMW 5.60; femur I 2.60; II 4.90; III 3.90; IV 4.70. Median paracheliceral projection slightly smaller than PAM. Ocularium next to anterior scutal margin; high, with 2 spines, 46 tubercles. Carapace with 69 scattered tubercles. Scutal area I with 43–47 scattered tubercles on each side; II with 98; III with 113 and a median spine oblique, curved subapically, not surpassing groove V; IV with 50 tubercles. Posterior margin of dorsal scutum with an irregular row of 17 tubercles, a regular row of 28. Free tergites I–II with an irregular row of 26 and 23 tubercles, respectively; III with 34 scattered tubercles. Anal operculum with 63 tubercles.

Venter: Coxa I with 43–49 tubercles, median and distal ones largest; II with 79–85, distal ones largest; III– IV irregularly tuberculate.

Chelicera: Segment I with 3 tubercles.

Pedipalpus: Trochanter dorsally inflated, with 4 tubercles. Femur dorsally with 4–5 aligned tubercles; ventrally with 1 large basal tubercle, 3 small aligned tubercles. Tibial setation: Prolateral and retrolateral IIi. Tarsal setation: Prolateral IIi, retrolateral IiIi.

Legs ( Fig. 2C–I): Coxa II with 7 tubercles on retrolateral margin; IV densely tuberculate, with 1 oblique prolateral apical apophysis, this conical, long, blunt, curved posteriad and slightly ventrad, with irregular projections on retrolateral margin. Trochanters I–IV densely tuberculate; IV prolaterally with 1 cylindrical median process, distally blunt and basally with a small, blunt, conical apophysis; retrolaterally with 2 large apical tubercles. Femora I–III with small PDS, RDS; I ventrally with 2 rows of slightly enlarged tubercles; II ventrally with 2 rows of tubercles, prolateral ones slightly increasing in size distally; III sinuous; ventrally with 2 rows of tubercles slightly increasing in size distally, 1 bifid PVS; IV sinuous, with small PDS, medium RDS; ventrally with 2 rows of tubercles, prolateral ones increasing in size distally, becoming high, pointed, 1 PVS. Tibia III ventrally with 2 rows of tubercles increasing in size subapically, becoming high, pointed, retrolateral ones enlarged, with 1 high, pointed, bifid tubercle; IV with 2 ventro-apical spines. Metatarsus I with 2 ventro-apical setae; IV with tubercles decreasing in size and number distally. Tarsal segmentation: 6, 9–10, 6, 6.

Penis ( Fig. 42E,F): Stylus with medio-ventral trichomes, slightly inflated apically; with angular medioventral projection. Ventral process of glans wide, curved, with apex blunt. Ventral plate with concave sides; with 3 pairs of slightly curved distal setae; 1 pair of short, straight, blunt median setae; 4 pairs of straight basal setae.

Coloration: Brown; legs dark brown, except for metatarsi and tarsi (light brown).

Female (paratype; MNRJ 5244): Dorsum: Measurements: SL 6.20; SMW 5.20; femur I 2.70; II 4.70; III 3.60; IV 4.50. Posterior margin of dorsal scutum and free tergites I–III with 83, 82, 75, 67 scattered tubercles, respectively. Anal operculum with 85 tubercles. Pedipalpus: Tibial setation: Prolateral IiIi/IIi, retrolateral iIIi/ iIiIi. Tarsal setation: Prolateral IIi, retrolateral IiIi. Legs: Coxa IV densely tuberculate, with 1 oblique prolateral apical apophysis, this conical, short, pointed. Trochanter IV densely tuberculate, retrolaterally with 1 large median tubercle, 1 short apical apophysis. Femur II with rows of similar-sized tubercles; III with slightly enlarged tubercles ventro-apically; IV with small PDS, RDS; ventrally with 2 rows of tubercles, prolateral ones slightly increasing in size distally, 1 short, trifid PVS. Tibiae III–IV with rows of similar-sized tubercles, without ventro-apical spines. Tarsal segmentation: 6, 8–9, 6, 6.

Variation in males (n=3): Measurements: SL 5.50–6.20; SMW 4.80–5.80; femur I 2.60–3.00; II 4.90– 5.20; III 3.80–3.90; IV 4.70–5.00. Femur I with reduced or small PDS, RDS; III with reduced or small PDS. The beta male shows the prolateral median process of trochanter IV as a conical structure.

Variation in females (n=2): Measurements: SL 5.80–6.20; SMW 5.10–5.20; femur I 2.60–2.70; II 4.70– 4.80. Pedipalpus: Tibial setation: Prolateral IiIi/IIi, retrolateral IiIi/iIIi/iIiIi.

Type locality: Brazil, Bahia, Ilhéus (Parataquicé) .

Geographical distribution ( Fig. 49A): Known only from the type locality.