Was Egypt’s desert once a shark-filled sea? Scientists uncover ancient ‘graveyard’

Palaeontologists have uncovered evidence of a remarkably rich marine ecosystem that existed in what is now Egypt’s desert millions of years ago, identifying teeth from seven shark species in rocks formed from an ancient seabed. The fossils were found on the Abu-Tartur Plateau in Egypt’s Western Desert, within the phosphate-rich Duwi Formation. The area was once part of a shallow sea that covered large parts of northern Africa during the Cretaceous period, between about 145 million and 66 million years ago.

The study, led by palaeontologist Tarek Yassin of Cairo University, was published in the journal Cretaceous Research under the title describing the shark assemblage from the Duwi Formation at Abu-Tartur.

Researchers examined 14 previously unreported shark teeth and identified five species that had not been recorded from Abu-Tartur before: Cretalamna cf. maroccana, Scapanorhynchus cf. raphiodon, Serratolamna cf. serrata, Squalicorax bassanii and Squalicorax pristodontus. Two of them, Serratolamna cf. serrata and Squalicorax bassanii, are also new records for Egypt.

One discovery was particularly significant. The needle-like teeth of Scapanorhynchus cf. raphiodon may represent the first known occurrence of the species in Africa and could be its youngest known fossil record, according to the researchers.

The findings point to a highly productive marine environment, likely fuelled by ocean upwelling that brought nutrient-rich deep water toward the surface. This would have supported plankton, fish and invertebrates, creating a food web capable of sustaining several large shark predators.

The researchers cautioned that the fossils do not prove all seven species lived in the area simultaneously. Limited sediment accumulation meant the phosphate deposits condensed remains from different periods and ecological settings.

“The presence of Squalicorax could suggest an input from nearshore/inner shelf settings, while the occurrence of Scapanorhynchus reflects deeper-water conditions on the outer shelf and slope,” the researchers wrote.