A new quantitative biochronological ordination for the Upper Neogene mammalian localities of Spain

Abstract

The MN scale is the most widely used biochronological scale for the mammalian fossil record of Europe but at the same time it has brought a high amount of criticism with it. The fossil record of Neogene macromammals from Spain is one of the most complete of the world and provides an interesting test of the MN biochronology.

We used maximum likelihood appearance event ordination (ML AEO), a quantitative biochronological method, to provide not only an ordination but also a numerical age estimate for each of the 90 macromammalian fossil faunas that constitute our data base. Originally, only 13 of these localities were numerically dated (mainly by means of paleomagnetism). The ordination of macromammalian fossil faunas matches quite well with the MN chronology at least in the Miocene. The pattern of ordination is less coherent in the Pliocene partly due to the relative poverty of macromammalian fossil sites of this age in Spain.

The controversy on whether the age of the first appearance of hipparionine horses in the Iberian Peninsula (Hipparion dispersal event) was around 10.8–10.7 Ma or 11.1 Ma is discussed. Our estimated MN7/8–MN9 boundary lies between 11.008 and 10.873 Ma. We conclude that the arrival of hipparionine horses in the Iberian Peninsula happened between these two ages and that the oldest record is found in the locality of Nombrevilla 1 with an age of 10.873 Ma.