The geographical and chronological pattern of herpetofaunal Pleistocene extinctions on the Iberian Peninsula

Abstract

Despite the postulation of the “herpetofaunal stability hypothesis”, which suggests that the herpetofauna underwent relatively few changes during the Pleistocene, the amphibian and squamate faunas of western Europe are known to have progressively diminished during the Pliocene and the beginning of the Pleistocene. Iberian Early Pleistocene sites continue to document the presence of “exotic” herpetofaunal elements that are supposed to have disappeared from the mainland, such as Oriental vipers, agamid lizards, the anguids Pseudopus and Dopasia, and a representative of the green toad group (Bufo viridis sensu lato), as well as possibly gekkonids, a scincid lizard (Lygosominae), the anguid Ragesaurus and blind snake (Scolecophidia). The geographical and temporal pattern of these progressive southward withdrawals and extirpations on the Iberian Peninsula shows that extirpation events occurred in northern Spain at roughly the Olduvai paleomagnetic event and in southern Spain just before the Jaramillo paleomagnetic reversal, thus permitting us to establish a framework that can be used to complement the biochronological zonation of the Iberian Early Pleistocene.