Nemastygnus 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 : 27-28

Nemastygnus Roewer, 1929 new family assignment

Nemastygnus Roewer, 1929: 277; Kury 2003: 145; (type species: Nemastygnus ovalis Roewer, 1929, by monotypy).

Diagnosis.

Nemastygnus was transferred from Cranaidae to Gonyleptidae , Metasarcinae by Kury (2003). It is closely related to Avima Roewer, 1949, based on dorsal scutum shape (rectangular) and scutal area III (unarmed). It is impossible to distinguish both genera mainly because Avima , the largest genus of Leiosteninae with 33 species, is a heterogeneous genus based on penial characters. The type-species of Avima , Avima leucobunus Roewer, 1949, is known only from the original description (and only external morphology). However, we will not propose synonymy in this paper because Nemastygnus is older and 33 new combinations should be proposed. A review of Avima plus Nemastygnus species is needed.

Description.

Ocularium unarmed, saddle-shaped. Areas and posterior margin of dorsal scutum and free tergites unarmed (Fig. 1A). Scutal area I undivided. Lateral margin of dorsal scutum coriaceus. Chelicera dimorphic. Pedipalp with slender articles; femur without dorsoapical spine, with row of three ventral large setae and two ventroapical large setae; patella with prolateral large setae; tibia–tarsus with ectal-mesal large setae. Leg I filiform, three-segmented. Penis: basal setae of truncus and basal setae of ventral plate very long and bifid; stylus with a large, longitudinal keel.