When an asteroid struck Earth about 66 million years ago, it ended the age of dinosaurs and transformed life across the planet. The effects of that catastrophe are visible in the fossil record on land, but scientists know far less about what happened to fishes in the seas during the first few million years after the extinction.
Like many people during the pandemic, I suddenly found myself living through long stretches of isolation and uncertainty. In 2020, while alone in my apartment in Ann Arbor, Michigan, I was finishing a study on fossil fishes from Egypt. This question of what happened to fishes immediately after the age of the dinosaurs kept troubling me.
That missing chapter represented a major gap in scientific understanding of how modern marine ecosystems emerged.
A unique opportunity
At the time, I was studying younger fossil fishes, but I kept wondering whether older rocks in Egypt might preserve clues to this critical period. During those long pandemic months, I spent countless hours reading geological reports and searching for mentions of formations with fish fossils of the right age.
Then, Hesham Sallam, my adviser, introduced me to earlier work by paleontologist and geologist Robert Speijer and colleagues who had documented rocks at Qreiya in Egypt that were deposited only about 4 million years after the asteroid impact.
That single detail changed the entirety of my Ph.D. research.
Professor Hesham Sallam, Mansoura University Vertebrate Paleontology Center
As this research started to point my work in a new direction, the pandemic was simultaneously disrupting my own life. I had been accepted into the Ph.D. program at the University of Michigan and was living in the United States, preparing to begin my studies. But COVID-19 restrictions suddenly forced me to return to Egypt, my home country. What felt like a major setback at the time ultimately became one of the most important turning points in my career.
While waiting for the embassies to reopen and student visas to be issued, I continued discussing the fossil-bearing rocks with my adviser. Those conversations soon became a plan: We would travel to Egypt’s eastern desert and see the site for ourselves.
Discoveries in the desert
In July 2021, our team of five researchers set out for Qreiya 3, a remote fossil locality in upper Egypt. Reaching the site required two days of travel from Mansoura. The terrain was so rough that our vehicles could take us only part of the way, forcing us to hike over sharp rocks carrying equipment, food, water and eventually fossil specimens.
Finding the fossil layer itself was not easy. With limited information about its exact location, we spent hours searching before finally reaching the end of a remote desert valley.
Then came a moment I will never forget. Belal Salem, a member of our team, struck the rock with his hammer. Almost immediately, a fossil moonfish appeared.
Professor Hesham Sallam, Mansoura University Vertebrate Paleontology Center
Moonfishes already held special significance for me because they were among the fishes I had previously studied from younger Egyptian rocks. Seeing one emerge from rocks that were millions of years older felt almost surreal, as though the site itself was answering the question that I had first asked during those quiet pandemic days.
It was the first sign that Qreiya 3 might be extraordinary.
Later that same field season, I received another unexpected email: My request for an expedited student visa appointment had been approved. We had only a few days to wrap up the expedition and return home so I could prepare for my departure to the U.S.
Returning to Qreiya 3
By the fall of 2021, I had begun my Ph.D. at the University of Michigan, and Qreiya 3 quickly became the center of my dissertation research.
These expeditions had revealed the promise of the site, but it was only the beginning. Over the following field seasons, our team continued returning to Qreiya 3, and I took part in the expeditions that gradually expanded our growing collection of fossils from the site curated at the Mansoura University Vertebrate Paleontology Center.
Professor Hesham Sallam, Mansoura University Vertebrate Paleontology Center
It became clear that this was not simply another fossil locality. It preserved an unusually rich fish community from a critical moment in Earth’s history, only a few million years after the extinction of the dinosaurs.
The biggest breakthroughs came during a 2023 expedition supported by a National Geographic grant awarded to Hesham Sallam. Once again, we returned in July, working under some of the harshest field conditions I have ever experienced. Temperatures often approached 122 degrees Fahrenheit (50 degrees Celsius), forcing us to organize each day around the heat. We worked early, paused during the most intense hours, drank water constantly and returned to the fossils whenever conditions allowed.
For three weeks, the Sallam Lab team excavated fossils under the intense desert sun. The work was exhausting, but every new specimen brought fresh excitement. By the end of the expedition, we had collected nearly 500 fossil specimens.
Piecing together an ancient ecosystem
Back in the laboratory, a different challenge began. Preparing the fossils was painstakingly slow. Removing the surrounding rock and exposing delicate anatomical details required years of careful work.
One fossil proved especially remarkable: an early relative of seahorses and pipefishes preserved with its body armor still intact.
Professor Hesham Sallam, Mansoura University Vertebrate Paleontology Center
Identifying the fishes often felt like solving an enormous puzzle. Some specimens were recognizable immediately, while others required months of comparison, CT scanning and detailed study.
I was fortunate to work under the supervision of Matt Friedman, one of the world’s leading experts on fossil fishes.
Gradually, the picture became clearer.
We began recognizing early relatives of tunas, jacks, moonfishes, pipefishes and other groups that today play major roles in marine ecosystems. Some are fast-moving predators and others are prey for these predators. The site provides direct evidence that several modern-looking fish groups were already established surprisingly early – only about 4 million years after the impact.
At the same time, just as revealing as what the site preserves is what it lacks. Many characteristically Cretaceous-era marine fish lineages are absent from the fossil assemblage, meaning they went extinct at or near the end-Cretaceous asteroid impact.
For me, Qreiya 3 is more than a fossil site. It is the place where an idea, an unexpected return home, years of desert fieldwork, and patient scientific investigation came together to reveal one of the clearest windows yet discovered into how modern ocean life began rebuilding itself after one of the greatest mass extinctions in Earth’s history.
