Ancient DNA elucidates the Quaternary history of the long-eared bats ( Plecotus , Chiroptera: Vespertilionidae) in Central Europe

The DNA analysis – and later, the ancient DNA analysis – has profoundly reshaped taxonomy, shifting it from a framework based primarily on morphology to one grounded in molecular evidence. Here it is demonstrated in a bat genus Plecotus, considered until 1960, a monotypic clade, in its current view comprising at least 20 separate extant cryptic species. A rich Quaternary fossil record of the genus used to be attributed to a fossil species Plecotus abeli Wettstein-Westersheim, 1923 described from a glacial assemblage in Austrian Alps, traditionally reported as an ancestor of extant Plecotus auritus (Linnaeus, 1758). Yet, two hypotheses are under investigation: (i) the separate species status of P. abeli is not substantiated, (ii) P. abeli is identical with extant P. auritus. Additionally, with a discovery of Plecotus macrobullaris alpinus Kiefer & Veith, 2002, a third hypothesis arose merging its identity with P. abeli (iii). We tested those hypotheses with the aid of detailed phenotype comparisons of extant clades and 790 fossil specimens, including the type series of P. abeli, as well as aDNA analysis of mid-European Late Pleistocene and Holocene samples of the genus, for which 42 bone and tooth samples from 20 sites across Central Europe were used. We successfully generated 35 mitogenomes, 29 belonging to Plecotus. They all, including the P. abeli paratype, were identified as P. auritus of the Eastern European clade. Thus, both our morphological and genetic data support that P. abeli is identical with P. auritus, rejecting hypothesis (iii), while (i) and (ii) are robustly supported. In consequence, vast majority of the Early Pleistocene and all the Middle and Late Pleistocene record of the genus (identified mostly as P. abeli) seems to belong to P. auritus, indicating at the same time a broad span of ecological plasticity and adaptive capacity of that species.