Description and phylogenetic position of a new species of Metarthrodes (Opiliones: Gonyleptidae: Caelopyginae) from Bahia, northeastern Brazil

Cruz Mendes, AmandaMartinho de Lima Barros, Carla

We describe Metarthrodes oxum sp. nov. from Camacan, state of Bahia, Brazil, the second species of Caelopyginae described from the state, after Metarthrodes xango Pinto-da-Rocha, 2002. Metarthrodes oxum sp. nov. can be recognized by the presence of a pair of white spots on area I, white C-shaped stripes on lateral grooves of area III, posterior margin with transverse white stripe, grooves of mesotergal areas well-marked, posterior margin of dorsal scute slightly concave, and medial third of femur IV of male with three large and spiniform retrolateral tubercles. We tested the generic placement of the new species via cladistic analysis. Metarthrodes oxum sp. nov. clustered within Metarthrodes, forming a clade with M. pulcherrimus (Mello-Leitão, 1931), M. nigrigranulatus Roewer, 1913 and M. longipes (Soares, 1945), which was unresolved in the consensus cladogram of the 72 optimal trees found, and is supported by the following synapomorphies (all present in males only): trochanter IV with long internal apophysis; retrolateral submedian tubercle on femur IV, and a pair of white spots near the groove. We also provide an updated identification key for the species of Metarthrodes.

1. Neotropical Region
2. harvestmen
3. Laniatores
4. Grassatores
5. taxonomy