Paleoenvironmental evolution of Central Anatolia during the Late Miocene: Multiproxy insights from the Çorakyerler hominine locality and regional records

Alçiçek H., Sevim Erol A., Neubauer T. A., Alçiçek M. C.

PALAEOGEOGRAPHY, PALAEOCLIMATOLOGY, PALAEOECOLOGY AN INTERNATIONAL JOURNAL FOR THE GEO-SCIENCES, cilt.699, ss.1-18, 2026 (SCI-Expanded, Scopus)

Özet

The middle Tortonian (MN11, early Turolian, 8.7 Ma) Çorakyerler locality in the Çankırı Basin (Central Anatolia, Turkey) preserves a taxonomically diverse vertebrate assemblage, including the hominine Anadoluvius turkae, within a paleosol-bearing fluvial succession. Integrated sedimentological, petrographic, isotopic, and faunal data indicate deposition in a low-gradient meandering fluvial system dominated by floodplain mudstones, pedogenic calcretes, and minor channel and crevasse-splay deposits. Floodplain mudstones exhibit root traces, desiccation cracks, mottling, and calcrete horizons, reflecting repeated phases of subaerial exposure, soil formation, and episodic flooding under seasonally dry but subhumid climatic conditions. Petrographic features such as brecciation, circumgranular cracking, and root traces document pronounced wet–dry cycles and pedogenic overprinting. Stable isotope compositions of pedogenic calcretes (δ18O = − 7.96 to − 5.02‰; δ13C = − 9.50 to − 2.38‰ VPDB) and associated organic matter (δ13Corg = − 27.50 to − 25.33‰ VPDB) indicate carbonate precipitation from meteoric soil waters in equilibrium with predominantly C3 vegetation. The weak negative correlation between δ13C and δ18O values (r = − 0.39) and the absence of strong positive covariance suggest pedogenesis under subhumid to seasonally dry climatic conditions with limited evaporative enrichment. Collectively, these multiproxy data indicate a heterogeneous landscape composed of riparian forests, woodland patches, wetlands, and open C3-dominated grasslands. The vertebrate community—including arboreal hominines, browsers, grazers, carnivores, and small mammals—corroborates this woodland–grassland mosaic. Taphonomic evidence indicates short- to moderatedistance transport and rapid burial of vertebrate remains in shallow floodplain depressions during episodic flood events, producing well-preserved assemblages formed during a limited number of flooding episodes and integrating taxa from adjacent habitats. Collectively, these multiproxy data indicate a heterogeneous landscape composed of riparian forests, woodland patches, wetlands, and open C3-dominated grasslands. Regional comparisons show that many Central Anatolian interior basins during MN11 shared warmtemperate, subhumid, C3-dominated woodland systems undergoing gradual structural opening. Çorakyerler succession stands out for preserving one of the most taxonomically diverse vertebrate assemblages and provides some of the clearest multiproxy evidence for ecological heterogeneity during this transitional interval, preceding the more pronounced vegetation opening and C4 expansion that characterized the late Tortonian–Messinian. Rather than representing a fully arid interior, the Çankırı Basin functioned as a seasonally variable but mesic plateau setting shaped by early orographic development and moderate rain-shadow effects. The persistence of C3-dominated woodland mosaics helps explain the survival of forest-associated taxa such as Anadoluvius turkae and highlights the role of Central Anatolia as a biogeographic corridor linking the Eastern Mediterranean, the Iranian Plateau, and the Balkans during the Late Miocene. Overall, the Çorakyerler succession offers a key