Friday June 5, 2026
National Geographic —
Paleontologists excavating a 62.2-million-year-old rock layer in Egypt have uncovered a petrified aquarium. The unexpected cache of fossilized fish—containing about 500 specimens from more than 20 types of ray-finned fish—offers a tantalizing look at how sea life bounced back from the asteroid impact that brought the Cretaceous to a crashing, fiery finale.
“When we arrived at the site and began finding well-preserved fish specimens in the sediment, we knew we were dealing with something exceptional,” says National Geographic Explorer Sanaa El-Sayed, a paleontologist at Mansoura University in Egypt. She and her colleagues published their findings on Wednesday in the journal Science Advances.
The dating of the rock layer places the ancient swimmers about four million years after the end of the Age of Dinosaurs and near the dawn of the Paleocene epoch. Paleontologists have spent decades piecing together how life reemerged once the blazes extinguished and the global “impact winter” subsided. On land, ferns underwent a major boom about a hundred thousand years after the extinction event. Fossil sites like Corral Bluffs in Colorado document how mammals, reptiles, and plants formed new forests a million years after the impact.