Global Climate Recovery and Marine Ecosystem Shifts Across the Oligocene–Miocene Transition: Foraminiferal Evidence From the Offshore Nile Delta, Egypt

Oligocene–Miocene transition (OMT) ∼23 million years ago was a critical global climatic change, involving Mi1 glaciation and later recovery. Multi‐proxy, high‐resolution investigation into foraminiferal assemblages from the offshore Nile Delta in the eastern Mediterranean (PFMD‐2R well) reconstructs significant regional late Oligocene to Miocene paleoenvironmental change. We report a marked postglacial warming and a significant increase in nutrient availability from the cool, oligotrophic, low‐oxygen Chattian conditions characterised by stressed assemblages with Globigerina glutinata to the warm, extremely productive, well‐oxygenated Burdigalian with diverse tropical–subtropical species such as Paragloborotalia semivera . The Aquitanian is characterised as a dynamic, transitory phase. Planktonic foraminifers were resilient, exhibiting high diversity throughout. Conversely, benthic assemblages were radically compromised in the Chattian, recovering later and indicative of a foundational inequality in ecosystem sensitivity. Paradoxically, this recovery correlated with a general shallowing trend of the water depth. Multivariate analyses affirm significant ecological reshaping attributable to post‐Mi1 climatic restoration. These semi‐restricted‐basin findings document the sophisticated interaction between global climatic forcing and regional responses in the ocean, stressing divergent biota recovery pathways between pelagic and ground‐dwelling biota.