The first Spinosaurus fossil was discovered in Egypt's Western Sahara in the beginning of the past century. The fossil unearthed in 1912, was named Spinosaurus aegyptiacus, in reference to the place it was discovered in.
It had long been thought that this dinosaur spent most of its time on the ground and only visited the river for drinking and feeding along its banks. But, Moroccan paleontologist Nizar Ibrahim first made the case for a semi-aquatic Spinosaurus in 2014. Then, earlier this year, he found a fossilized Spinosaurus tail, which suggested the spinosaur was not just semi-aquatic but largely aquatic. So much so, the team declared its tail the first "unambiguous evidence for an aquatic propulsive structure in a dinosaur."
The Moroccan paleontologist's theory remained controversial until the discovery of a sheer abundance of spinosaur teeth in the prehistoric Kem Kem river system, which once flowed from Morocco all the way to Algeria. The new discovery, which was announced in the latest issue of the Cretaceous Research journal, came to support Ibrahim's theory.
In a field survey carried out by Moroccan and British paleontologists in southeastern Morocco, the researchers discovered fossilized remains from the site of an ancient river bed including 1,200 teeth of dinosaurs and aquatic animals, with almost half of them belong to Spinosaurus.
According to researchers, the enhanced abundance of Spinosaurus teeth, relative to other dinosaurs, is a reflection of their aquatic lifestyle.
In a report published Saturday on the Science Alert website, David Martill, professor of palaeobiology at the University of Portsmouth, said: "An animal living much of its life in water is much more likely to contribute teeth to the river deposit than those dinosaurs that perhaps only visited the river for drinking and feeding along its banks. Spinosaurus teeth are distinct and easily identifiable compared to any other dinosaur or aquatic animal."