Although the green toad (Bufo viridis) can today be found all over Central Europe, Asia, Africa, and even on the Balearic Islands, it became extinct in the Iberian Peninsula at the end of the Early Pleistocene (1.1 million years ago). This has been demonstrated by an international research study, with Spanish participation, which has discovered the first green frog fossil in Murcia.
Analysis of fossils found in the Cueva Victoria deposit in Cartagena (Murcia), has for the first time confirmed the presence of the green toad (Bufo viridis) in south eastern Spain at the end of the Early Pleistocene (more than 1.1 million years ago), in the provinces of Granada, Murcia and Castelln.
"Around 500 fossilised bones document the entire skeleton of the green toad, and provide key osteological clues that mean they can be unequivocally attributed to this species", Hugues-Alexandre Blain, one of the authors of the study and a researcher in the Prehistory Department at the Rovira i Virgili University (URV) in Tarragona, tells SINC.
The study, which has been published in Comptes Rendus Palevol, shows that at this time the amphibian belonged to a different subspecies than the green toads of today. Changes in the climate and landscape, "which have taken place frequently over the past two million years", could be the reason for them having become locally extinct.
Nowadays, B. viridis is distributed extensively throughout Eurasia and northern Africa, but until now its presence had never been demonstrated in the Iberian Peninsula. "Although the peninsula has favourable ecological conditions, the species is strangely absent", the expert says.
The south western limit of its current range in Europe is the border between Italy and France. In Spain, it is only found in the Balearic Islands, "where it is thought to have arrived recently, possibly having been introduced by the Phoenicians from northern Africa", says
FECYT - Spanish Foundation for Science and Technology