As-Sahabi at the crossroads: Current palaeontological knowledge and future perspectives

The Libyan fossil site of As-Sahabi provides critical insight into the ecology and biogeography of North Africa during the late Miocene to early Pliocene, a period marked by significant climatic and tectonic changes. As-Sahabi preserves a rich assemblage of vertebrates, ichnofauna, and fossil wood, deposited along the now-vanishing Eosahabi River System. This study synthesises a century of research, from early Italian excavations and collections in the 1920s to recent work by the International Sahabi Research Project (ISRP) and East Libya Neogene Research Project (ELNRP). The stratigraphy of the site reveals four key formations: Benghazi (late Miocene), Sahabi (late Miocene), Qarat Weddah (Pliocene), and Shagig (late Pliocene - Pleistocene). The fossil record comes primarily from the Sahabi and Qarat Weddah formations and includes 51 mammalian, 10 avian, 29 fish, and 5 reptilian species, reflecting a mixture of African and Eurasian taxa. Semiaquatic mammals, such as Libycosaurus and freshwater fish, indicate a fluvial deltaic environment, while marine taxa such as sirenians and cetaceans suggest episodic marine incursions. Spatial analyses reveal strong correlations between herbivores (Bovidae, Anthracotheriidae) and carnivores, suggesting predator-prey dynamics, while taphonomic studies highlight fluvial transport as a key depositional process. Despite extensive taxonomic work, quantitative paleoecological analyses remain limited. Biases in collections, particularly toward micromammals and reptiles, complicate ecological interpretations. Future work should integrate ecology, geochemistry, and spatial modelling to refine habitat reconstructions and assess the impact of the Messinian Salinity Crisis on terrestrial ecosystems. This study highlights the importance of As-Sahabi as a paleobiogeographic crossroads and calls for renewed interdisciplinary research to clarify chronostratigraphy and unresolved Neogene palaeobiological questions. • The As-Sahabi site in northeastern Libya is a critical fossil site, providing key insights into late Miocene-Pliocene ecosystems of North Africa; • Renowned for its exceptional taxonomic and ecological diversity, As-Sahabi preserves a distinct mix of marine, terrestrial species and flora; • The site once hosted a mosaic of coastal, freshwater, and terrestrial environments, shaped by the interplay of the Mediterranean Sea and the now-vanished Eo-Sahabi River; • As-Sahabi's fauna reveals a blend of African and Eurasian species, highlighting late Miocene dispersal routes and intercontinental migrations; • Study of its fossils offers crucial evidence on ecological and climatic shifts during the Messinian Salinity Crisis.