There is a place that palaeontologists half-jokingly call “the most dangerous in Earth’s history”. It is the Kem Kem beds in south-eastern Morocco: the deposits of a vast river system that flowed about a hundred million years ago, in the middle of the Cretaceous. Today they are reddish cliffs on the edge of the Sahara. Back then, a humid delta where the density of large predators has no parallel in the known terrestrial record.
Too Many Predators
In the Kem Kem deposits lie side by side Spinosaurus — one of the largest known carnivorous dinosaurs, a semi-aquatic fisher with a sail on its back; Carcharodontosaurus — a land predator the size of Tyrannosaurus; and Deltadromeus — a swift runner. By the rules of ecology, so many large predators should not exist in one territory. The answer probably lies in the river feeding them all: fish, including giant coelacanths and Onchopristis — ancient relatives of sawfish — formed the basis of the food web.
What Comes from Kem Kem
For a collector, Kem Kem is a source of teeth and bones of Cretaceous predators: Spinosaurus teeth with their characteristic smooth conical crowns, fragments of Carcharodontosaurus, bones and vertebrae. It is important to understand that isolated teeth are common here, while complete associated skeletons are an exceptional rarity, and the market is flooded with composites. That is why a Kem Kem provenance demands especially rigorous verification.
The Discipline of Provenance
Moroccan extraction means hundreds of local diggers and long chains of middlemen, where the context of a find is easily lost. That is why, for finds from Kem Kem, it is especially important that the geology of the matrix matches the declared horizon and that the provenance is documented.
Kem Kem is valuable not only for its objects but for the picture itself: a world that broke our rules and existed all the same. To hold a tooth from there is to touch an ecosystem that is hard to believe in.