British scientists help establish first 'river monster' dinosaur was aquatic

British scientists have discovered that the first “river monster” dinosaur was equipped with a huge fin-like tail to help it nimbly swim and catch prey at rapid speeds.

The fossilised tail of the Spinosaurus aegyptiacus, unearthed in Southern Morocco last year, forms part of the remains of the huge 15-metre-long predator which used to trawl the ancient rivers of the Sahara desert for prey 100 million years ago.

Weighing six tonnes, the flat footed beast with short hind legs was not thought to be semi-aquatic upon its discovery in Egypt 100 years ago, as it was believed dinosaurs lived exclusively on land.

Now, an international team of experts, including those from the University of Portsmouth and Southampton, have confirmed that the Spinosaurus was the first fully aquatic dinosaur which likely only left the river to lay eggs, following an anatomical examination of its whole tail.

With the help of Harvard researchers, the teams attached a model of the tail to a robotic system that mimics swimming movements in order to compare its performance to comparable dinosaurs and crocodiles.

They concluded that the Spinosaurus had to be a “water-dwelling, tail-propolled” dinosaur as its tail vertebrae had extremely long spines, supporting a “fin-like”  tail similar in shape to a crested newt.

Researchers involved in the project have hailed the revelations as “game changing”, describing it as the “nail in the coffin for the idea that non-avian dinosaurs never invaded the aquatic realm.”

David Martill, professor of palaeobiology at the University of Portsmouth, told The Daily Telegraph: “We have just discovered that the Spinosaurus aegyptiacus was an aquatic dinosaur. We already had suggestions that it had aquatic adaptations a couple of years ago but no one took us seriously.

“The first thing we noticed a couple of years ago is that its nostrils were further back. One idea was that if you are around a river bank feeding, it is better if your nostrils are a bit further back when putting your muzzle near the water. Also, its feet are absolutely flat and would make an excellent padal if they were webbed.”

“Now we have discovered the tail and found that it is absolutely adapted to an aquatic existence.”

He added: “In the world of dinosaurs we are extremely excited as there are all sorts of questions like how come dinosaurs didn't become aquatic before this?”

The study, published in the journal Nature, was also carried out by experts from the University of Detroit Mercy, in Michigan, the University of Casablanca, in Morocco, and the Natural History Museum of Milan.