The rodent succession in the Sifón de Librilla section (Fortuna Basin, SE Spain): implications for the Mio-Pliocene boundary in the Mediterranean terrestrial record

Abstract

The long and continuous continental section of Sifón de Librilla (Fortuna Basin, southern Spain) provides a detailed biostratigraphic record distributed along eight localities, in which the magnetostratigraphy has been unambiguously established. This section therefore provides a unique opportunity to cross biostratigraphic information with magnetostratigraphic data to establish a reliable frame to date sites. This 800-m-thick sequence extends from the latest Miocene to the early Pliocene, recording more than 2 Myr. Here we provide a complete taxonomic survey of the recovered rodent remains, defining a new cricetid species named as Hispanomys romeroi. We also refine the phylogenetic relationships of the Apodemus, Stephanomys, Paraethomys, Ruscinomys and Apocricetus lineages. Considering the accurate age of the associations, we discuss the chronology of the first and last appearances of some species. In addition, this section clearly records the Mio-Pliocene boundary, allowing us to correlate between the marine and continental biostratigraphic scales. Taking advantage of this opportunity, we explore key biostratigraphic indicators for identifying the beginning of the Pliocene in the continental records, as well as for differentiating the MN13 and MN14 units, most specially the FOD of Occitanomys brailloni. According to this datum, we conclude that the Miocene-Pliocene boundary coincides with that of MN13-MN14 units. http://www.zoobank.org/urn:lsid:zoobank.org:act:BDA60E97-C23B-482D-AD0D-9C25FDF5FA05

Keywords:

• Late Miocene
• early Pliocene
• MN13/MN14
• biostratigraphy
• chronology
• marine/continental correlation

Acknowledgments

The authors thank to the editor Gareth Dyke and the reviewers Raef Minwer-Barakat and Hugues-Alexandre Blain for their comments and suggestions on the manuscript. We are especially grateful to Manel Llenas for his help in the sampling and proccessing of the materials here studied, and made this paper possible.