Abstract
Fossil material from 90 fossil localities, mostly paleokarstic, has been gathered together to study western European bat evolution and diversity from the middle Eocene (~44 Ma) to the early late Oligocene (~29 Ma). The morphological and biometric observations and comparisons of the tooth material allow recognition of 7 families, 10 genera and 57 species; amongst the latter, 45 are described in detail here together with 11 subspecies. Several taxa of various systematic ranks are described as new: 1 subgenus and 17 species including 6 new subspecies; 1 new family and 2 new genera were described in a previously published paper but originate from this large review. From these new results, and the long period covered (more than 10 Ma), this work suggests a number of phyletic hypotheses. Amongst others, the relationship between the new fossil family Mixopterygidae and the fossil and extant families Emballonuridae and Hipposideridae is discussed. The peculiar Necromantis fossil genus being now better documented, its particular inferior molar pattern is exemplified as defining the necromantodont pattern. Even though the affinities of Necromantis remain unclear, the new data indicate that the previous assignment to Megadermatidae was incorrect. Thanks to the available information from the bat material, the relative dating of yet unstudied and undated new localities is proposed from biochronal reference stages, characterized by some bat species with a given size and morphology. Also, further data are given for faunas dated by the numerical ages method. The comparison of fossil and modern bat cenograms suggests that the body weight composition of a community is linked to the nature of the environment in which it evolves. Finally, these analyses allow deducing some possible bat evolutionary modalities either by the variations in the represented weight range or by the proportion of the different weight categories. They indicate that extinctions preferentially affected “extreme species” from a morphological point of view, as well as in terms of body mass. Consequently, this allows discussion of the effect of Stehlin’s faunal Grande Coupure faunal event amongst western European bats at the Eocene–Oligocene boundary.
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