Comment on egusphere-2025-6383

Abstract

Abstract. The Eocene–Oligocene Transition (EOT dated at ~34 Ma) represents one of the most significant climatic shifts of the Cenozoic, marking the transition from the last warmhouse state to a coolhouse state. This global cooling had major consequences for terrestrial ecosystems and was synchronous with the dispersal of numerous Asian mammalian clades towards western Europe. However, the terrestrial expression of the EOT exhibits strong regional heterogeneity. Consequently, its role in establishing dispersal corridors associated with the Grande Coupure remains unclear. Here, we describe, date, and document the paleoenvironments of a continental sedimentary section from Balkanatolia, a biogeographic province that most likely functioned as a critical stepping stone for the dispersal of Asian mammals toward western Europe. Our sedimentary record represents a fluvio-lacustrine system dated by magnetostratigraphy to the Priabonian and the lower Rupelian, including the Oi-1 glaciation (~33.65 Ma). Clumped isotopic analyses on pedogenic carbonates across our record show evidence for a Late Eocene Warming starting during the middle Priabonian (ca. 37 Ma), followed by a marked cooling event at the Eocene–Oligocene Glacial Maximum (EOGM). Stable isotopic data and sedimentary facies further indicate that this complete interval is associated with a long-term aridification trend, starting during the Late Eocene warming and culminating at the EOT. Our results provide the first quantitative record of late Eocene warming on land, and our temperature estimates for the earliest Oligocene cooling are consistent with other Eurasian clumped-isotope records. These temperature shifts and associated aridification steps may have acted as contributing drivers of the late Eocene decline of Balkanatolian endemic taxa and likely facilitated the westward expansion of Asia-derived mammals ultimately resulting in the colonization of western Europe.

Authors 13

1. Paul Botté corresponding

   Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement · Centre de Recherche et d’Enseignement de Géosciences de l’Environnement · Institut de Recherche pour le Développement

   Affiliation as printed

   Aix Marseille University, CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France

2. Alexis Licht

   Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement · Centre de Recherche et d’Enseignement de Géosciences de l’Environnement · Institut de Recherche pour le Développement

   Affiliation as printed

   Aix Marseille University, CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France

3. Anne‐Lise Jourdan

   Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement · Centre de Recherche et d’Enseignement de Géosciences de l’Environnement · Institut de Recherche pour le Développement

   Affiliation as printed

   Aix Marseille University, CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France

4. Lény Montheil

   Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement · Centre de Recherche et d’Enseignement de Géosciences de l’Environnement · Institut de Recherche pour le Développement

   Affiliation as printed

   Aix Marseille University, CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France

5. François Demory

   Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement · Centre de Recherche et d’Enseignement de Géosciences de l’Environnement · Institut de Recherche pour le Développement

   Affiliation as printed

   Aix Marseille University, CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France

6. Mustafa Kaya Aachen Geological Institute

   RWTH Aachen University

   Affiliation as printed

   Geological Institute, RWTH Aachen University, Aachen, Germany

7. Faruk Ocakoğlu

   Eskişehir Osmangazi University

   Affiliation as printed

   Department of Geological Engineering, Eskişehir Osmangazi University, Eskişehir, Türkiye

8. Mehmet Serkan Akkiraz

   Kütahya Dumlupınar Üniversitesi

   Affiliation as printed

   Department of Geological Engineering, Kütahya Dumlupınar University, Kütahya, Türkiye

9. Deniz İbilioğlu

   Kütahya Dumlupınar Üniversitesi

   Affiliation as printed

   Department of Geological Engineering, Kütahya Dumlupınar University, Kütahya, Türkiye

10. Pauline M. C. Coster

    UNESCO

    Affiliation as printed

    Réserve naturelle nationale géologique du Luberon, Unesco Global Geopark, Parc naturel régional du Luberon, Apt, France

11. Grégoire Métais

    Centre National de la Recherche Scientifique · Sorbonne Université · Muséum national d'Histoire naturelle · Centre de recherche en paléontologie - Paris

    Affiliation as printed

    Centre de recherche en paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle, Sorbonne Université, CNRS, Paris, France

12. Benjamin Raynaud

    Centre National de la Recherche Scientifique · Sorbonne Université · Muséum national d'Histoire naturelle · Centre de recherche en paléontologie - Paris

    Affiliation as printed

    Centre de recherche en paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle, Sorbonne Université, CNRS, Paris, France

13. K. Christopher Beard

    University of Kansas

    Affiliation as printed

    Biodiversity Institute, University of Kansas, Lawrence, Kansas, USA

    Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, USA