Napostygnus bispinosus Roewer, 1929

Pinto-da-Rocha, Ricardo, Benedetti, Alipio Rezende, de Vasconcelos, Eduardo Gomes & Hara, Marcos Ryotaro, 2012, New systematic assignments in Gonyleptoidea (Arachnida, Opiliones, Laniatores), ZooKeys 198, pp. 25-68 : 29-30

Napostygnus bispinosus Roewer, 1929 Fig. 3

Napostygnus bispinosus Roewer, 1929: 275, fig. 42 (♀); Kury 2003: 145; (female holotype, Ecuador, Napo, Valley of Rio Napo, SMF RI 1004/3, examined).

Material examined.

ECUADOR. Napo: Valley of Rio Napo, 1 female holotype (SMF RI 1004/3); Cantón Quijos, Parroquira Cozanga, Yanayacu Research Station (0°35'S, 78°57'W, 2128 m), 1 ♂ & 2 ♀ (MZSP 36132); ditto, 1 ♀ (IBSP 10550).

Description.

Male (MZSP 36132). Dorsum (Fig. 3A). Measurements: dorsal scutum length 4.1; dorsal scutum maximum width 3.5; carapace length 2.1; carapace maximum width 2.9; femur IV length 11.2. Body outline nearly subrectangular. Anterior margin of dorsal scutum with a median frontal hump small-granulate. Ocularium near middle of carapace, saddle shaped, with small granules near the eyes, unarmed. Carapace higher than the rest of dorsal scutum, with 4 tubercles behind ocularium. Scutal areas I–III with 2 small median tubercles on each area; IV with 4 tubercles. Lateral margin of dorsal scutum with a low density of small granules. Posterior margin of dorsal scutum and free tergite I with a row of small granules, unarmed. Free tergites II–III each with a median spine, small granulate.

Chelicera: segment I unarmed. Segment II swollen, finger II with 3 teeth, III with 4 teeth.

Pedipalpus: trochanter with 2 ventral tubercles, femur and patella smooth. Tibial setation: retrolateral iiIii; prolateral iiiIiii. Tarsal setation: retrolateral IiIi; prolateral IiiiIi.

Legs: legs I–IV unarmed and without granules, except for trochanters, which are small granulate. Basitarsus I slightly inflated. Tarsal process present. Tarsal segmentation: 6(3); 16(3); 6; 7.

Penis (Fig. 3 B–C): ventral plate with almost straight distal margin, thick median lobe and folded ventrally to the distal setae, 3 pairs of distal setae and 2 pairs of basal setae. Glans with thumb-like dorsal process. Stylus with dorsal apical projection and ventral apical small trichomes.

Coloration (in ethanol) (Fig. 3A): body background yellow with brown spots mainly on carapace, scutal areas, lateral and posterior margins of dorsal scutum and free tergites. Mesotergum with one longitudinal yellow stripe surrounded by blackish pigment at grooves I–V. Pedipalpus and chelicera yellowish brown with a brown reticulate pattern. Legs yellowish brown.

Taxonomical note.

Napostygnus was originally placed in Gonyleptidae , Prostygninae . Kury (1994b) transferred Prostygninae to Cranaidae and later transferred Napostygnus to Gonyleptidae , Metasarcinae ( Kury 2003). We herein propose the removal of Napostygnus from Metasarcinae based on male genitalia, which does not present the diagnostic character for the subfamily ( Kury and Maury 1998; Kury and Pinto-da-Rocha 2007b), viz., a pair of spiny laterobasal sacs on the ventral plate. Another remarkable difference from Metasarcinae is the unarmed ventral pedipalpus femur. The combination of characteristics of penis and body morphology does not allow placing Napostygnus bispinosus in any other family of Laniatores which bear tarsal process on legs III–IV. The slightly swollen male basitarsus I is not equal to those of Manaosbiidae , and furthermore the genitalia is distinct, since it possesses a dorsal process. The ocularium resembles those of Gonyleptidae , Bourguyiinae , but the penis is not similar, because there is only a dorsal process and no ventral process. The aspect of the penis resembles those of Cranaidae (presence of dorsal process, ventral plate and setae shape) and therefore, we propose its transfer to this family. It is noteworthy to mention that the morphology of the body of Napostygnus bispinosus is somewhat distinct from the typical Cranaidae . We will not assign it to any subfamily, following the opinion of Orrico and Kury (2009) on the meaninglessness of current subfamily classifications in Cranaidae .