Recent research on early bats has shown that diversification began early in the Early Eocene. The diversity was the highest in Europe and India and composed of the families Onychonycteridae, Icaronycteridae, Archaeonycteridae, Palaeochiropterygidae, and Hassianycteridae. However, in Europe, the oldest species have all been described from Northern Europe with the exception of Archaeonycteris? praecursor from Silveirinha (MP7, Portugal). Here we present a new bat from La Borie (MP8+9, South France). It is the first early Eocene species from Southern Europe identified on a relatively complete dentition: about 40 isolated teeth and dentary fragments. The teeth are nyctalodont and characterized by: moderate sized canines; middle sized p4 with well-developed metaconid; wide m1-2 with very lingual hypoconulid and high entoconid; middle sized P4; M1-2 with deep ectoflexus, weak paraconule, weak to absent metaconule, centrocrista not joining the labial border; m3/M3 smaller than m1-2/M1-2. These characters indicate that this species belongs to the Archaeonycteridae and is close to Archaeonycteris. It differs from Archaeonycteris trigonodon from Messel (MP11, Germany), A. brailloni from Mutigny and Avenay (MP8+9, France), and Protonycteris gunnelli from Vastan (India) by being about 25 % smaller. It is similar in size to Archaeonycteris? praecursor, A? storchi from Vastan, and the new archaeonycterid from Meudon (MP7, France). It differs from A? storchi by smaller p4 and shallower dentary, and from the Meudon species by more lingual hypoconulid, higher entoconid, and longer postcristid. In fact, it is very similar to A? praecursor by the m2 with relatively high entoconid and long postcristid; the main difference being the hypoconulid that is a little more lingual. The latter character suggests a more advanced dilambdodonty than A? praecursor, which is in agreement with the ages of the two localities. Both species seem to belong to the same evolutionary lineage geographically restricted to Southern Europe.

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Paleontology