Résumé
Freshwater environments play an essential role in shaping ecosystems, yet their reconstruction often remains secondary to terrestrial ones in paleoenvironmental studies in intertropical African sites. However, understanding freshwater ecosystems is crucial, as they intersect hydrography, climate, and biodiversity, by influencing species distribution and survival. The Toros-Menalla fossil area in northern Chad (ca. 7 Ma) provides a unique window into Late Miocene ecosystems, preserving an exceptional vertebrate assemblage, including Sahelanthropus tchadensis, the earliest known hominin. Although aquatic environments are supposed to have been abundant in Late Miocene landscapes of Toros-Menalla, detailed characterizations of its freshwater species habitats are still lacking.We investigate the diversity of freshwater environments in Toros-Menalla through the study of aquatic and semi-aquatic vertebrate assemblages (actinopterygians, crocodilians, chelonians, and hippopotamoids), from five sites selected based on consistent sampling strategies, extensively focusing on aquatic vertebrates. By examining community composition, skeletal element representation, and fossil preservation, we assess how sampling and taphonomic processes influence paleoecological interpretations. Community composition and structure were further analysed in relation to habitat preferences and ecological tolerances, providing insight into waterbodies diversity.Our results, contextualized with previously published and unpublished isotopic data, shows that each site correspond to a specific freshwater environment. They thus reveal various perilacustrine environments displayed along the margin of a Late Miocene mega lake stage, including floodplain, drying pond, and vegetated marginal environments.