Maioricalacerta rafelinensis, gen. et sp. nov. (Squamata, Lacertidae), from the early Pliocene of Mallorca (Balearic Islands, western Mediterranean Sea)

Abstract

ABSTRACT Here we describe a new genus and species of Lacertidae, Maioricalacerta rafelinensis, gen. et sp. nov, a large-sized lizard with amblyodont teeth from the early Pliocene (Zanclean) of Mallorca (Balearic Islands, western Mediterranean Sea). The presence of amblyodont teeth separates Maioricalacerta from recent species of Lacertidae. Maioricalacerta differs from the amblyodont lacertids of the European Tertiary (Quercycerta, Escampcerta, Mediolacerta, Pseudeumeces, Dracaenosaurus, Amblyolacerta, and Ligerosaurus) in the anteroposterior and mediolateral widening of the teeth and in the wide lateral wall of the dentary, which is massive, relatively short, and robust. Dracaenosaurus displays a similar morphology of the dentary, but the number of teeth is lower and they are more amblyodont than in Maioricalacerta. The dentition observed in Maioricalacerta suggests that the diet of the species was related to a consumption of hard prey, perhaps molluscs. The length reduction of the dentary constitutes an evolutionary biomechanical advantage to consume this kind of prey as it improves jaw-closing force. However, its movement is likely to have been slower but potentially more accurate. The robustness of the dental structures in Maioricalacerta also contributes to enhance the resistance of the bone against the increased static pressure to which it is subjected during jaw closure. Maioricalacerta is the most Recent amblyodont lacertid known and the only one described from the Pliocene of Europe.