A team of researchers has uncovered an extensive fossil fish assemblage in Egypt’s eastern desert that sheds new light on marine life in the critical period following the asteroid impact that ended the age of dinosaurs about 66 million years ago. The discovery helps fill a significant gap in understanding how modern marine ecosystems developed in the early Paleogene epoch.

The research originated during the COVID-19 pandemic when University of Michigan doctoral student Sanaa El-Sayed began investigating fossil fishes from Egypt. While initially focused on younger specimens, El-Sayed’s work took a pivotal turn after she was introduced to prior studies on the Qreiya site in upper Egypt, which preserves rock formations dating to roughly four million years after the mass extinction event. This timeframe is crucial because it represents a period poorly understood in marine evolutionary history.

In July 2021, El-Sayed joined a five-member team on an expedition to Qreiya 3, a remote fossil locality that required challenging travel, including hiking over rugged desert terrain to reach the fossil-bearing strata. The team spent hours locating the specific fossil layer before discovering well-preserved remains, including a fossil moonfish. The presence of such species, previously known only from younger deposits, suggests continuity and diversification of marine fish communities shortly after the extinction event.

The discovery of Qreiya 3’s fossil fish assemblage provides rare evidence of marine life dynamics just a few million years after the Earth's most devastating extinction, offering insight into the recovery and evolution of marine ecosystems. The fossils are now curated at the Vertebrate Paleontology Center of Mansoura University, where ongoing study is expanding understanding of early Paleogene marine biodiversity.

El-Sayed’s research underscores the importance of the Qreiya 3 site as a key location for studying early post-extinction marine environments. Despite pandemic-related challenges, including travel restrictions and visa delays, the team’s continued fieldwork since 2021 has enriched the fossil record from this period, contributing valuable data to paleontology and evolutionary biology.