Patterns of variation in Microtus arvalis and Microtus agrestis populations from Middle to Late Pleistocene in southwestern Europe

Abstract

Fifteen paired fossil populations of Microtus arvalis and Microtus agrestis from southwestern Europe have been analysed from a morphological and morphometric point of view. The sites under consideration are located in the northern Iberian Peninsula and southern France, from the Middle Pleistocene to the end of the Late Pleistocene. The aim of this study is to stress once again the importance of keeping these two species separated in the fossil record in order to recognize specific trends of evolution and divergence and to obtain more precise information on palaeoclimatic and palaeoenvironmental conditions. It was possible to observe remarkable intraspecific differences between Middle and Late Pleistocene populations of both species. Furthermore, in synchronic co-specific populations from the Late Pleistocene, climatic and geographic conditions seem to exert a major influence in shaping intraspecific changes in dental pattern.

Keywords:

• Morphology
• morphometric
• dental variation
• Microtus

Acknowledgements

The authors want to thank all those who provided the material for this study: Dr Xosé Pedro Rodríguez and Arturo de Lombera (Cova Eirós), Dr Manuel Vaquero (Valdavara), Dr Gloria Cuenca-Bescós (Atapuerca), Dr Francesc Xavier Oms (Colomera), Dr Julià Maroto (Arbreda and Mollet), Dr Jordi Rosell, Dr Ruth Blasco and Dr Florent Rivals (Teixoneres and Toll), Dr Gema Chacón, Dr Palmira Saladié and Dr Josep Vallverdú (Abric Romaní) and Dr Joan Madurell-Malapeira (Carrière). We would also like to thank the editor Dr Gareth Dyke and the two anonymous reviewers for their comments, which strongly improve the final version of the manuscript. The authors want to thank Rupert Glasgow for the revision of the English manuscript. E.L. is beneficiary of a PhD scholarship funded under the Erasmus Mundus Program – International Doctorate in Quaternary and Prehistory.