2D Geometric morphometrics of the first lower molar of the genus Meles Brisson, 1762 including new badger evidence from the Lower Pleistocene Quibas site (Murcia, Spain)

Badgers belong to the genus Meles Brisson, 1762, which comprise four extant species (M. anakuma Temminck, 1844, M. leucurus (Hodgson, 1847), M. canescens Blanford, 1875, and M. meles (Linnaeus, 1758)). The genus is included in the subfamily Melinae Bonaparte, 1838, a polyphyletic group of Eurasian mustelids whose evolutionary relationships need further clarification. The evolutive relationships of the genus are complex and far from being resolved. This work aims to describe a nearly 1 Ma unpublished badger mandible from the Sierra de Quibas (Murcia) and to help clarify the evolutionary patterns of Euroasiatic badgers. To this end, we used 2D geometric morphometric techniques to measure 57 landmarks and semilandmarks in 79 first lower molars (m1) of Meles, ranging from Pleistocene to extant species. Our results show evidence for differentiating between primitive badgers and living species of Meles. The new m1 of Meles from the Quibas site is more gracile (relatively narrower and longer) than the other Eurasian extinct species, and shows that this specimen can be placed in the subspecies M. meles meles (Linnaeus, 1758). Our results also show that the denomination of M. meles atavus Kormos, 1914 as a related subspecies with a primitive morphology is morphologically supported. Therefore, we conclude that the living subspecies of badger M. meles meles was already differentiated in the south of the Iberian Peninsula at around 1 Ma, but some primitive remnant populations persisted in the north of the Iberian Peninsula, for which we recognize the subspecies M. meles atavus.