Cladistic analysis of the Stygninae and description of a new species of Protimesius Roewer, 1913 (Opiliones: Stygnidae)

A new species of Stygnidae is described from the state of Bahia, Brazil. Protimesius bahiensis sp. nov. can be distinguished from the remaining species of the genus by the combination of: male femur IV unarmed and cylindrical; male patella IV with a row of large dorsal acute tubercles, increasing in size distally and male tibia IV with one mesodistal tubercle; ventral plate of the penis with three pairs of distal curved setae and one pair of intermediate setae, smaller than the rest. A cladistic analysis of the subfamily is presented. Stygninae is divided in two groups of genera: (Ricstygnus, Stygnus, Sickesia), with a wide distribution and (Pickeliana (Protimesius (Phareus (Stenophareus (Auranus (Verrucastygnus, Stenostygnoides)))))), associated to the Guiana Shield, Amazon basin and Northeastern Brazil. The monophyly of Protimesius is supported by the apex of pedipalpal tibia sockets bifid (homoplastically present in Verrucastygnus and Stenostygnoides) and by the presence of scopulae with non-spatulated hairs.