Updated Aragonian biostratigraphy: Small Mammal distribution and its implications for the Miocene European Chronology

Authors

  • A.J. VAN DER MEULEN Faculty of Earth Sciences, Utrecht University. Budapestlaan 4, 3584 CD Utrecht, The Netherlands.
  • I. GARCÍA PAREDES Departamento de Paleobiología, Museo nacional de Ciencias naturales MNCN-CSIC. C/ José Gutiérrez Abascal 2, 28006 Madrid, Spain. Netherlands Centre for Biodiversity-naturalis. Darwinweg 2, 2333 CR Leiden, The Netherlands.
  • M.A. ÁLVAREZ SIERRA Departamento de Paleontología, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid. IGEO-CSIC. C/ José Antonio Novais 2, 28040 Madrid, Spain.
  • L.W. VAN DEN HOEK OSTENDE Netherlands Centre for Biodiversity-naturalis. Darwinweg 2, 2333 CR Leiden, The Netherlands.
  • K. HORDIJK Faculty of Earth Sciences, Utrecht University. Budapestlaan 4, 3584 CD Utrecht, The Netherlands.
  • A. OLIVER Departamento de Paleobiología, Museo nacional de Ciencias naturales MNCN-CSIC. C/ José Gutiérrez Abascal 2, 28006 Madrid, Spain.
  • P. PELÁEZ-CAMPOMANES Departamento de Paleobiología, Museo nacional de Ciencias naturales MNCN-CSIC. C/ José Gutiérrez Abascal 2, 28006 Madrid, Spain.

Keywords:

Rodents, Lagomorph, Insectivores, Miocene, Faunal events

Abstract

This paper contains formal definitions of the Early to Middle Aragonian (late Early–Middle Miocene) smallmammal biozones from the Aragonian type area in North Central Spain. The stratigraphical schemes of two of the best studied areas for the Lower and Middle Miocene, the Aragonian type area in Spain and the Upper Freshwater Molasse from the North Alpine Foreland Basin in Switzerland, have been compared. This comparison allows the analysis of the order of shared mammal events in the two countries, and the quantification of the resulting asynchronies based on their temporal correlations. The order of the events is very similar in Spain and Switzerland. In order to estimate the diachrony, two age-model options are used for the Swiss record. Our preferred option yields no discrepancies with SW European paleomagnetic and radiometric calibrations of the Ramblian and Early Aragonian bioevents. All Swiss first taxa occurrences precede those in the Aragonian type area by 0.74Myr on average. The asynchronies (1-2Myr) of the species arriving in the late Middle to early Late Aragonian may be higher than in the Early Aragonian (0-1Myr). The implications for the biochronological mammal Neogene system are discussed. Evidence is given confirming the unfeasibility of a formal European biozonation, since it is realised, that 1) most indicator species and many genera of rodents yielding the most detailed zonations have limited geographical ranges hampering recognition of the mammal Neogene zones; and 2) first and last taxon occurrences are diachronical. Therefore, the mammal Neogene system based on a sequence of time-ordered reference localities is preferred to the one based on selected bioevents “developed in widespread geographic areas”.

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Published

2012-07-20

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Articles