Fossil tortoises from the middle to late pleistocene of Buena Pinta Cave (Pinilla del Valle, Central Spain): implications for the altitudinal record of Chersine hermanni and conservation strategies

Abstract

The Hermann’s tortoise (Chersine hermanni), an endangered species, currently ranges from eastern Spain to the Balkans and some Mediterranean islands, though fossil evidence shows a wider past distribution. This study analyses the chelonian remains recovered from Buena Pinta Cave site (Middle to Late Pleistocene), the most complete with semi-articulated specimens from the Calvero de la Higuera Archaeological Complex (Pinilla del Valle, Madrid, central Spain). The morphology of these remains is consistent with C. hermanni. Taphonomic analysis suggests that carnivore activity and water transport were responsible for the accumulation of the assemblage. The nearly complete carapace from Unit 23 may represent an individual that died potentially naturally during brumation. The presence of Chersine hermanni at high altitudes in central Spain (~1,100 metres above sea level) during the middle and Late Pleistocene exceeds the current maximum elevation for the western subspecies (850 metres) and is more comparable to that recorded for the eastern subspecies (1,450 metres). These findings suggest the Iberian populations of C. hermanni had a broader ecological tolerance in the past, inhabiting higher-altitude areas and climatic conditions not currently found within its current range. These results highlight the importance of considering historical distributions when developing conservation strategies for endangered species.