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The late Miocene is a period of increasing aridity and habitat openness in the south-eastern Mediterranean region. The impact of these changes has not been fully explored regarding rhinocerotids' ecology, although rhinoceroses were a major and diverse component of the Miocene mammalian faunas. Here, we investigate the palaeoecology of rhinocerotid specimens coming from 12 localities throughout the Balkan-Iranian zoogeographic province, and covering a large part of the late Miocene (MN9 to MN13). Microwear textures confirmed the hypothesised niche partitioning between the two main rhinocerotid species – Ceratotherium [Ce.] neumayri (mixed-feeder including grasses) and Dihoplus pikermiensis (browser) – but highlighted dietary overlap between Ce. neumayri and the co-occurring chilothere species at Maragheh, Samos and Pentalophos-1. Although microwear did not reveal clear spatiotemporal differences, we found obvious discrepancies regarding hypoplasia prevalence: Vallesian rhinocerotid teeth displayed more defects (Xirochori and Pentalophos-1: 16.26% of teeth affected) than Turolian specimens (all other localities: 9.72%). Similarly, rhinocerotid teeth from eastern localities (Samos and Maragheh; supposedly more arid), had a higher hypoplasia prevalence (13.52%) than their western counterparts (6.90%). Insights from rhinocerotids' ecology thus challenged space and time homogeneity within Balkan-Iranian province, and the associated savanna habitat, at least regarding the sample studied here. [ABSTRACT FROM AUTHOR]

Eurasia was home to a great radiation of hominoid primates during the Miocene. All were extinct by the end of the Miocene in Western Eurasia. Here, we investigate the hypothesis of climate and vegetation changes at a local scale when the cercopithecoid Mesopithecus replaced the hominoid Ouranopithecus along the Axios River, Greece. Because they are herbivorous and were much more abundant than primates, bovids are preferred to primates to study climate change in the Balkans as a cause of hominoid extinction. By measuring carbon stable isotope ratios of bovid enamel, we conclude that Ouranopithecus and Mesopithecus both evolved in pure C3 environments. However, the large range of δ 13C values of apatite carbonate from bovids combined with their molar microwear and mesowear patterns preclude the presence of dense forested landscapes in northern Greece. Instead, these bovids evolved in rather open landscapes with abundant grasses in the herbaceous layer. Coldest monthly estimated temperatures were below 10°C and warmest monthly temperatures rose close to or above 20°C for the two time intervals. Oxygen isotope compositions of phosphate from bulk samples did not show significant differences between sites but did show between-species variation within each site. Different factors influence oxygen isotope composition in this context, including water provenience, feeding ecology, body mass, and rate of amelogenesis. We discuss this latter factor in regard to the high intra-tooth variations in δ 18Op reflecting important amplitudes of seasonal variations in temperature. These estimations fit with paleobotanical data and differ slightly from estimations based on climate models. This study found no significant change in climate before and after the extinction of Ouranopithecus along the Axios River. However, strong seasonal variations with relatively cold winters were indicated, conditions quite usual for extant monkeys but unusual for great apes distributed today in inter-tropical regions. [ABSTRACT FROM AUTHOR]