Three islands, three worlds: paleogeography and evolution of the vertebrate fauna from the Balearic Islands

The Balearic Islands are an archipelago located in the Western Mediterranean Sea. Their isolation from the mainland allowed the establishment of different faunas on each of them. While in Mallorca the Pliocene fauna was composed of the so called Myotragus-fauna (mainly consisting of a bovid, a glirid and a soricid), in Menorca it was constituted by the giant rabbit-fauna (mainly consisting of a giant rabbit and a tortoise), and in the Pityusics by a tortoise, a lizard and two rodents. A main faunal turnover took place during the Late Pliocene or Early Pleistocene: the Myotragus-fauna reached Menorca and substituted the giant rabbit fauna. In the Pityusics, all mammals and the tortoise became extinct before the Late Pleistocene for unknown reasons, leaving birds and the lizard as the only vertebrates of these islands. Almost all the endemic vertebrates of the Balearics became extinct probably due to the first human arrival to the islands.