Crocodiles came from Africa: much earlier than we thought. We could thus summarize and simplify the new study published on Zoological Journal of the Linnean Society and produced by a team from Mansoura University, in Egypt, which analyzes an exceptional fossil found in the Western Desert, the area of the Sahara located west of the Nile.
These are the remains of a saltwater crocodile that lived eighty million years ago, and therefore pushes back by about ten million years the moment in which these reptiles appeared and began to diversify.
A name, a guarantee. We talked about “crocodile” but it would be more correct to use the plural “crocodiles”: the Egyptian team has in fact found the remains of four different individuals, each at a different stage of growth, and represented by their skulls. The animals were identified as a new species, named Wadisuchus kassabi: the generic name means “crocodile of Wadi al-Jadid”, the governorate where the fossil was found, while the specific one is a tribute to the Egyptian paleontologist Ahmed Kassab.
The first marine crocodiles. Wadisuchus belonged to the family Dyrosauridaeancestors of crocodiles distributed throughout the world since the Cretaceous and disappeared only in the Eocene, after having survived the extinction of the dinosaurs. THE Dyrosauridae they were saltwater crocodiles, characterized by a long, thin snout and sharp teeth that they used to capture “slippery” prey such as fish.
Until now, we thought that the Dyrosauridae appeared and began to diversify in the Maastrichtian, around 72 million years ago; the new fossil pushes this back by about ten million years, and confirms that the origin of marine crocodiles is in North Africa.
Dimensions and features. Wadisuchus kassabi it was, according to the description read in the study, a crocodile between 3.5 and 4 meters long, with a very long snout and equally long and sharp teeth. Compared to other members of its family it only had four teeth on the tip of its snout (other saltwater crocodiles have five), and the nostrils positioned on the top of its snout allowed it to breathe underwater. All these traits indicate an adaptation to aquatic ecosystems, which will then be found in the other Dyrosauridae and their modern descendants.
Fossils to be protected. In addition to being fundamental for understanding the evolution of crocodiles, the fossil is, according to the authors, also a way to remember that Western Sahara is a treasure chest of fossils that has not yet been fully explored.
“Our mission” said one of the study authors “is also to protect these fossil-rich sites from urban and agricultural expansion, and leave them as a legacy to future Egyptian generations”.