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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The rich earliest Eocene mammal assemblage of Dormaal in northeast Belgium has yielded most of the earliest modern mammals of Europe and is the the reference-level for MP7 in the Mammalian Biochronological Scale of the European Paleogene. Despite the fact that several other localities in Europe, such as Silveirinha in Portugal, Le Quesnoy, Pourcy, Sotteville-sur-Mer, Rians, Palette, and Fordones in France, and the Suffolk Pebble Beds in England, contain faunas that have been correlated to Dormaal, none of them preserve the same fauna as Dormaal with the exception of Erquelinnes in southwest Belgium. Here we describe the new vertebrate site of Clairoix, located only 13 km from Le Quesnoy in the Paris Basin, France, but 225 km southwest of Dormaal. About 150 kilograms of sandy matrix has produced a collection of about 400 vertebrate specimens including 118 isolated mammal teeth. The fauna is composed of the following typical MP7 species: the herpetotheriid marsupial Peratherium constans, the amphilemurid erinaceomorph Macrocranion vandebroeki, the hyaenodonts Arfia gingerichi and Prototomus minimus, the carnivoraforms Dormaalocyon latouri and Gracilocyon solei, and the omomyid primate Teilhardina belgica. Besides these index taxa, the arctocyonid Landenodon woutersi, the louisinid “condylarths” Paschatherium dolloi and Paschatherium yvetteae, a perissodactyl, and several rodents also are present at Clairoix. As in Dormaal, the relative abundance analysis of the species from Clairoix indicates that P. dolloi and P. yvetteae are the most abundant species, followed by M. vandebroeki and T. belgica, respectively. In term of number of specimens, Paschatherium represents more than 50% of the fauna, which corresponds to the acme of Paschatherium defined across the Paleocene–Eocene boundary in continental Europe. The composition and relative abundance of the mammal fauna of Clairoix are very similar to those of Dormaal and Erquelinnes and suggest a similar or very close age. The results of this work also suggest that the mammal assemblage of these three localities does not only correspond to a different paleoenvironment than that of other MP7 correlated faunas but also to an older age closer to the Paleocene–Eocene Thermal Maximum. Fish, frog, lizard, crocodilomorph, and snake remains were also collected and support a fluvial paleoenvironment at Clairoix. Grant Information This research was supported by the BRGM ‘Régolithe’ Scientific Program and the Belgian Science Policy Office (project BR/121/A3/PalEurAfrica).
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