Protimesius osvaldoi sp. nov. is described from the Reserva Biológica de Sooretama, state of Espírito Santo, southeastern Brazil, being the first record of Stygnidae from this State and the southernmost record of the family in the Brazilian Atlantic Forest (hitherto, the family was recorded down to Bahia only), extending in 210 km south of the previously known distribution. This is a large species, with armature of leg IV very reduced and penial morphology differing from the closest counterparts mainly in the ventral plate, which recedes deeply at the lateral borders and has the distal margin curved ventrally and by the presence of two small intermediate setae. Protimesius Roewer, 1913 consisted hitherto of 17 species, recorded from northern/northeastern Brazil and Amazonia of adjacent countries. A key is given for the 17 species of Protimesius for which males are known.
Atlantic Forest; harvestmen; neotropics
