First known gigantic sea turtle from the Maastrichtian deposits in Egypt

The Maastrichtian deposits in Egypt and generally in Africa contain very few records of chelonioids. This scarcity hinders understanding the evolution and extinction of African chelonioids during this age. The Dakhla Basin in Egypt presents excellent Maastrichtian outcrops that consist of highly fossiliferous, calcareous siltstone and sandstone layers rich in ammonites, bivalves (Exogyra overwagi, Pyawdonta vesicularis, pectinids), gastropods, echinoids, corals, fossilized fruits of mangrove plants (Nypa) and vertebrate remains. The well-preserved humerus of giant turtle and other vertebrate remains have been discovered in the early late Maastrichtian Ammonite Hill Member of the Dakhla Formation in the Abu Minciar area, Southern Western Desert, Egypt. The Ammonite Hill Member was deposited in very shallow coastal, inner neritic to littoral environments. The well-preserved giant humerus represents the rust record of gigantic Mesozoic chelonioids in Africa and the second record of chelonioids in the Maastrichtian deposits in Egypt. The present specimen contributes to fill the missing gaps in the history of Egyptian turtles from the Cretaceous through the Cenozoic.

Automated summary

The Maastrichtian deposits in Egypt and Africa have limited records of chelonioids, hindering understanding of their evolution and extinction during this period. The Dakhla Basin in Egypt has provided valuable fossils that help fill gaps in the history of African turtles and contribute to research on their evolution and extinction during the Late Cretaceous.