The wild horses and donkeys of Europe are two of the megafauna species that became extinct during the Late Quaternary Extinction Event. Until now, the most widely accepted hypothesis was that the decline of steppe ecosystems, caused by global temperature increase that determined the end of the Ice Age, was the main cause of the vanisghing of these equids and other mammals such as woolly mammoths or rhinoceros. The published work provides evidence supporting the idea that human activities, such as competition for the same resources due to the introduction of livestock farming, may have played a more significant role in their extinction than previously thought. 

In paleontology, the study of species' dentition provides valuable information about their diet. Through the analysis of tooth wear, it is possible to infer what they ate and, consequently, reconstruct their habitat. In this study, researchers Daniel DeMiguel and Flavia Strani analyzed the fossil dental remains of wild horses and donkeys excavated in La Carihuela (Granada), which inhabited the southern Iberian Peninsula during the Ice Age, between 115,000 and 11,700 years ago. By examining the small marks left by food during the chewing process on the tooth surfaces, they determined that both species shared the same ecological niche. While their dentition was adapted to the vegetation typical of the steppe, they could also have fed on types of vegetation. 

This dietary flexibility introduces a new perspective on the causes of the extinction of Equus ferus and Equus hydruntinus, as it would have allowed them to adapt and survive even after climate change, when the steppe was no longer the dominant landscape. Therefore, the causes of their extinction would be more related to human action than environmental changes. 

The research team responsible for the study emphasizes that it is essential to understand how large mammals responded to past climate changes in order to better understand the effects of current global warming on future scenarios. Additionally, this understanding helps us grasp the current situation of present-day species and promote efficient conservation measures to protect those at risk of extinction. 

Daniel DeMiguel is an ARAID (Fundación Agencia Aragonesa de Investigación y Desarrollo) researcher affiliated to the Instituto Universitario de Investigación en Ciencias Ambientales de Aragón (IUCA) of the Universidad de Zaragoza. He is also a research associate at the Institut Català de Paleontologia Miquel Crusafont. Flavia Strani is a Juan de la Cierva researcher affiliated to IUCA and Sapienza Università di Roma. 

Main image: artwork of the life appearance of Equus ferus and Equus hydruntinus. Roc Olivé / © Institut Català de Paleontologia Miquel Crusafont. With the collaboration of Fundación Española para la Ciencia y la Tecnología – Ministerio de Economía, Industria y Competitividad.

Article reference:

• Strani, F., & DeMiguel, D. (2023). The role of climate change in the extinction of the last wild equids of Europe: Palaeoecology of Equus ferus and Equus hydruntinus during the Last Glacial Period. Palaeogeography, Palaeoclimatology, Palaeoecology, 620, 111564. https://doi.org/10.1016/j.palaeo.2023.111564