First report of geophilid centipedes of the genus Ribautia (Myriapoda: Chilopoda: Geophilomorpha) from the Atlantic Forest biome, with description of a new miniature species from Misiones Province, Northeastern Argentina.

Ribautia paranaensis sp. nov. a new miniature species of geophilid centipede from the Upper Paraná Atlantic Forest (the westernmost of the fifteen ecoregions comprising the Atlantic Forest biome sensu Di Bitetti et al. 2003), is herein described and illustrated. The new species is characterized by having the coxal organs grouped in clusters (one of these in each coxopleuron of the ultimate leg-bearing segment) and a claw-like pretarsus in the ultimate legs; these traits being shared by three other Neotropical members of the genus, i.e., R. combinata Pereira, Uliana & Minelli, 2006 (from the Amazonian rainforest of Peru), R. jakulicai Pereira, 2007 (from the Yungas rainforest of Northwestern Argentina), and R. lewisi Pereira, 2013 (collected in a gallery forest in the Mesopotamian region, Northeastern Argentina). R. paranaensis sp. nov. represents the first report of Ribautia Brölemann, 1909 in the entire Atlantic Forest biome, and the third confirmed record of the taxon from Argentina.