The ‘most dangerous place’ in the history of the world

100 million years ago, "ferocious predators", including flying reptiles and crocodile-like hunters, made the Sahara the most dangerous place on Earth  - according to scientists.

An international team of palaeontologists have carried the biggest review in almost 100 years of fossil vertebrates from an area of Cretaceous rock formations in south-eastern Morocco, known as the Kem Kem Group.

The review is published in the open- access journal ZooKeys and "provides a window into Africa's Age of Dinosaurs," according to lead author Dr Nizar Ibrahim, an Assistant Professor of Biology at the University of Detroit Mercy and Visiting Researcher from the University of Portsmouth.

The Kem Kem Group is a well-documented area known for its highly fossiliferous rock formations. This area contains  records of lifeforms on Earth, spanning tens of millions of years. 

It is filled with many different species of both aquatic and terrestrial animals, as well as a plethora of plants.

The area previously known as the “kem kem beds” consists of two distinct formations, the Gara Sbaa Formation and the Douira Formation - which is now described collectively as the Kem Kem Group.

More recent research has shown that this area was also home to three of the largest predatory dinosaurs ever known, including the sabre-toothed Carcharodontosaurus (over 8 metres in length with enormous jaws and long, serrated teeth up to eight inches long) and Deltadromeus (around 8 metres in length, a member of the raptor family with long, unusually slender hind limbs for its size), as well as several predatory flying reptiles (pterosaurs) and crocodile-like hunters.

"This was possibly the most dangerous place in the history of planet Earth, a place where a human time traveller would not last long," said Dr Ibrahim. 

Experts from the Universities of Detroit, Chicago, Montana, Portsmouth (UK), Leicester (UK, David Unwin), Casablanca (Morocco), and McGill (Canada), as well as the Paris Museum of Natural History compared expedition notes and records of the Kem Kem formation over decades, and reviewed data sets from fossil records housed in museums around the world. 

This research is described as "the most comprehensive piece of work on fossil vertebrates from the Sahara in almost a century," which has produced invaluable information about Africa's ancient past, explained Professor David Martill from the University of Portsmouth.

"This place was full of absolutely enormous fish, including the giant coelacanth and the lungfish (dipnoi). The coelacanth, for example, is probably four or even five times larger than the current coelacanth, and there's a huge freshwater saw shark called Onchopristis with the most fearsome front teeth on the planet; they're like barbed daggers, but wonderfully bright.” explained Professor Martill. 

To assemble the huge datasets and fossil images, which were originally included in his PhD thesis, lead author Dr Ibrahim visited Kem Kem collections on several continents.

The Sahara desert of today’s world remains one of the most unforgiving places on Earth - but for different reasons. It's hot, dry, barren landscapes are home to some of the most blinding dust storms. 

Reference: Ibrahim, N., et al, 'Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco', ZooKeys, (21 April 2020), 928, 1-216 doi: 10.3897/zookeys.928.47517