Paleontologists have discovered fossilised teeth from at least seven shark species in the arid Abu Tartur desert of Egypt.
The discovery shows that the dry plateau was part of a rich marine ecosystem tens of millions of years ago during the Cretaceous period. Global ocean levels were significantly higher between 145 million and 66 million years ago, submerging much of North Africa beneath shallow, warm seas.
Research published by ScienceAlert indicates that phosphate deposits in the region hold crucial evidence about the environmental conditions of that ancient body of water.
Phosphate rock deposits
Researchers studied sediment layers in the Duwi Formation, a geological structure in the Egyptian desert known for its rich phosphorite deposits. Phosphorite rocks typically form in marine environments with high biological productivity, where phosphorus actively circulates and accumulates over extended periods.
Earlier field research led by paleontologist Tarek Yassin of Cairo University had uncovered fossilised teeth from two shark species at the Abu Tartur site. Those initial findings suggested that the prehistoric marine environment was productive enough to sustain multiple apex predators.
A subsequent investigation uncovered 14 additional teeth belonging to five species never before recorded at the location. In total, researchers have confirmed that at least seven distinct shark species inhabited the ancient marine layer.
Diverse hunting strategies
The newly recovered teeth were identified as the remains of five extinct species of sharks. In marine ecology, physical variations in tooth structure indicate that predators occupied separate ecological niches, allowing them to coexist without competing directly for the same food sources.
Some of the sharks possessed broad, serrated teeth adapted for cutting into large prey, whereas others had long, slender teeth suited for catching fast marine animals. Distinct shapes in their lateral cusps also point to different hunting methods among the extinct species.
Gradual accumulation over time
Scientists warned against interpreting the site as a literal shark cemetery where multiple species died simultaneously in a single event. Because phosphate sediments accumulate very slowly, the fossil-bearing layer spans a vast stretch of geological time.
The shark teeth accumulated gradually across various ecological zones over long periods as the animals naturally shed them. The findings provide further proof that the northern coast of Africa was a major center for marine life near the close of the Cretaceous era.
Other historical discoveries
In other recent archaeological developments, researchers on the Faroe Islands uncovered a medieval runic stone bearing an inscription that translates to Here Lies. The monument was discovered inside an early Christian worship site alongside an oil lamp and a sculpture of the Virgin Mary holding the infant Jesus.
In Turkey, archaeologists unearthed a 2,400-year-old hoard of silver coins decorated with images of wrestlers. The coins, found near burial sites showing physical trauma, shed new light on the lives of classical-era athletes.
