In short: the Kem Kem beds are Cretaceous river and delta sediments in eastern Morocco, near the Algerian border. They preserve one of the most predator-rich ecosystems ever found, including Spinosaurus and Carcharodontosaurus, and they are the source of most dinosaur teeth from Morocco.
Where and how old?
The beds form a long escarpment in southeastern Morocco. A major 2020 scientific review formally named them the Kem Kem Group, made of the lower Gara Sbaa Formation and the upper Douira Formation. The researchers date them to the Cenomanian, the first stage of the Late Cretaceous, roughly 100 to 95 million years ago.
A landscape of rivers and deltas
Today the area is dry desert. During the Cenomanian it was a network of rivers flowing toward the sea, full of fish, turtles and crocodile-like reptiles. Most fossils are found as isolated teeth and bones rather than complete skeletons, because river currents scattered remains before they were buried.
The most dangerous place on Earth?
The Kem Kem fauna is unusual because it is dominated by large carnivores. The 2020 review lists at least four large meat-eating dinosaurs living in the same region:
- Spinosaurus, the sail-backed giant adapted to hunting fish in and around water.
- Carcharodontosaurus, a huge predator with blade-like, serrated teeth.
- Deltadromeus, a lightly built theropod.
- An abelisaurid, a short-snouted predator.
They shared the rivers with several large pterosaurs, large crocodyliforms such as Elosuchus, and giant fish. The sawfish-like Onchopristis is among the most common Kem Kem fossils. Plant-eating dinosaurs are rare, although the long-necked sauropod Rebbachisaurus is known from partial remains.
Why so many teeth?
Large predatory dinosaurs shed and replaced teeth throughout their lives. Each animal could lose many teeth, and these hard, enamel-covered objects survive well in river sands. That is why Spinosaurus and Carcharodontosaurus teeth are relatively common, while bones and skulls are rare.
Identifying Kem Kem dinosaur teeth
Spinosaurus teeth are conical with fluted enamel and smooth edges. Carcharodontosaurus teeth are flat, curved and serrated. Read our full guide: Spinosaurus vs Carcharodontosaurus Teeth.
Kem Kem vs the phosphate basins
The Kem Kem beds are older and formed on land, so they hold dinosaurs. The phosphate basins near Khouribga are younger marine deposits from the very end of the Cretaceous, so they hold mosasaurs and plesiosaurs. Learn more about the Oulad Abdoun Basin.
Explore
Sources
- Ibrahim N. et al. (2020). Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco. ZooKeys 928: 1–216. doi:10.3897/zookeys.928.47517