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International audience; The Myotis nattereri species complex consists of an entangled group of Western Palaearctic bats characterized by fringing hairs along the rear edge of their uropatagium. Some members are relatively common while others are rare but all forms are morphologically very similar and their taxonomy is unresolved. Recent studies based on different molecular markers have shown that several major and unexpected lineages exist within this group of forest-dwelling bats. All the mitochondrial and nuclear markers tested to date have shown that these major lineages evolved as fully independent and coherent units and therefore each qualifies as distinct species. In the absence of proper morphological diagnosis, these lineages are informally referred to in the literature under different names. We explore here the external and craniodental variation of these lineages. Although all morphological measurements were overlapping between these lineages, we show that lineages can be completely discriminated in a multivariate morphometric space. Consistent with previous molecular reconstructions, these four major lineages represent two pairs of related species, each represented by a named species (Myotis nattereri s. str. and M. escalerai, respectively) and by unnamed forms (Myotis sp. A and Myotis sp. B, respectively). Herein we describe formally these two unnamed forms to clarify the taxonomy within this species complex. This new taxonomic view has important implication for the protection of these species, as three of the four taxa must now be considered as range-restricted species in need of conservation actions.

The contemporary distribution and genetic composition of biodiversity bear a signature of species’ evolutionary histories and the effects of past climatic oscillations. For many European species, the Mediterranean peninsulas of Iberia, Italy and the Balkans acted as glacial refugia and the source of range recolonization, and as a result, they contain disproportionately high levels of diversity. As these areas are particularly threatened by future climate change, it is important to understand how past climatic changes affected their biodiversity. We use an integrated approach, combining markers with different evolutionary rates and combining phylogenetic analysis with approximate Bayesian computation and species distribution modelling across temporal scales. We relate phylogeographic processes to patterns of genetic variation in Myotis escalerai, a bat species endemic to the Iberian Peninsula. We found a distinct population structure at the mitochondrial level with a strong geographic signature, indicating lineage divergence into separate glacial refugia within the Iberian refugium. However, microsatellite markers suggest higher levels of gene flow resulting in more limited structure at recent time frames. The evolutionary history of M. escalerai was shaped by the effects of climatic oscillations and changes in forest cover and composition, while its future is threatened by climatically induced range contractions and the role of ecological barriers due to competition interactions in restricting its distribution. This study warns that Mediterranean peninsulas, which provided refuge for European biodiversity during past glaciation events, may become a trap for limited dispersal and ecologically limited endemic species under future climate change, resulting in loss of entire lineages.

Aim The role of glacial refugia in the biogeographical patterns in the Western Palaearctic region has been widely discussed, but many questions remain unre- solved. We examined the biogeography, genetic diversity, spatial distribution and evolutionary history of the Myotis nattereri bat species complex to investi- gate the presence of multiple refugia and the persistence of Quaternary differ- entiation between and within Mediterranean refugia in a flying mammal. Location Western Palaearctic region (central and southern Europe and north- western Maghreb). Methods We analysed three mitochondrial fragments (cytochrome b, NADH dehydrogenase subunit 1 and the control region; 1570 bp) from 136 individu- als of the M. nattereri complex sampled from 87 different localities using a range of phylogenetic techniques. Divergences among clades were also dated using a Bayesian coalescence approach. Results Phylogenetic analyses identified four main lineages, coincident with the four cryptic species recently described. Each species is further subdivided into well-supported lineages with evident geographical structure. Estimates of genetic diversity and polymorphism were very high for the majority of subclades, with the exception of M. nattereri s.s. Main conclusions The M. nattereri bat complex comprises four species whose distributions in the Western Palaearctic correspond to four main glacial refugia (Iberia, Italy, Balkans and Morocco). These species are the result of long-term isolation (remarkable in a flying mammal) over several glacial cycles. The Balkan species expanded into central Europe in a rapid recolonization pro- cess. Both the Iberian and Italian peninsulas show a clear pattern of refugia- within-refugia in their genetic structuring, with a deeply differentiated southern Italian clade. Morocco shows two markedly differentiated lineages, probably separated by the Atlas Mountains. The legacy of Pleistocene cycles is evident in both the speciation and the intraspecific diversification events.