The phylogeny of the genus Roquettea Mello-Leitão, 1931 and its position in Discosomaticinae are investigated. The monophyly of an expanded Roquettea is for the first time tested and corroborated. The internal relations of Roquettea are elucidated by means of a morphological maximum parsimony cladistic analysis. Synapomorphies for the genus include: pedipalpal tibia forming long lobe projected anteriorly; supranumerary ventral plate macroseta grouped with macrosetae C; penis ventral plate projections and stylus with beak. New characters are proposed for the Cosmetidae species and genera, and special focus is placed on the finer study of the glans complex, with a fresh proposal of homology for its constituent parts and their evolution in the light of the topology proposed here. Roquettea bubalina, sp. nov. and Roquettea troguloides, sp. nov. are described respectively from the Brazilian states of Mato Grosso and Pará. Both species present unique dorsal protuberances and unusual ocularia. New material of previously described species of Roquettea is available, increasing our knowledge on the genus. The following new semaphoronts are described and illustrated: β male of R. carajas Kury & Ferreira, 2012; females of R. decioi Kury, 2013, R. taurina Ferreira & Kury, 2010 and of R. jalapensis Ferreira & Kury, 2010. An emended diagnosis and an identification key are provided for the species of Roquettea including all known semaphoronts.