A new fauna has been collected from a fissure filling named Cos in the Quercy region, southwestern France. It includes four primate species and a plesiadapiform. The cercamoniine adapiform Protoadapis andrei Godinot and Vidalenc, nov. sp., is represented by material that adds to our knowledge of the genus Protoadapis for the upper canine, upper molars and other morphological details. It appears more primitive than P. brachyrhynchus from the Old Quercy Collections. The other cercamoniine Pronycticebus cosensis Godinot and Vidalenc, nov. sp., offers insight on intraspecific variations and other details of the genus. Both species suggest a bushy evolution within these genera. Two teeth document the presence of a third cercamoniine, Anchomomys sp. indet. The new microchoerid Quercyloris eloisae Godinot and Vidalenc, nov. gen., nov. sp., has very primitive characters and seems to document a primitive member of the Pseudoloris clade. A poorly documented paromomyid plesiadapiform is distinct enough to be named Arcius moniquae Godinot and Vidalenc, nov. sp. It represents the first discovery of a plesiadapiform in the Quercy fossil record and makes a link with paromomyids surviving until the late Lutetian European Mammal Paleogene MP 13 reference level. The primates indicate a broad age interval between MP10 (late Ypresian) and MP 12 (mid-Lutetian). The identification of the same species of Pronycticebus and of the new genus in the Vielase fauna suggests more precisely the MP 10–MP 11 (late Ypresian–early Lutetian) time interval.