Spinosaurus: Earth's First Swimming Dinosaur

Scientists have unearthed Spinosaurus aegyptiacus, which was not only the biggest and baddest of all the carnivores, but also appears to be the first known swimming dinosaur, according to new research.

At more than 50 feet (15 meters) nose to tail - bigger even than the mighty Tyrannosaurus rex - this semi-aquatic dino adapted to life in the water some 95 million years ago,  providing the most compelling evidence to date of a dinosaur able to live and hunt in an aquatic environment.

Researchers from the University of Chicago uncovered the new fossils, described in the journal Science, in sandstone beds in the Moroccan Sahara desert. Complete with skull, claws, and bones that formed the sail on its back, the fossils reveal a crocodilian snout, paddle-like feet, and dense bones that aided buoyancy, adding up to a successful life in the water for this giant predator.

"It was the biggest carnivorous dinosaur, but Spinosaurus wasn't a land animal," lead author Nizar Ibrahim, a University of Chicago paleontologist, told National Geographic. "This was a creature adapted to life in the water."

While other ancient creatures, such as the plesiosaur and mosasaur, lived in the water, they are marine reptiles rather than dinosaurs, making Spinosaurus the only-known semi-aquatic dinosaur.

These river giants supposedly feasted on animals like giant sharks and other car-sized fish called coelacanths and lungfish, the researchers added.

Scientists had long known of this creature's existence - Spinosaurus aegyptiacus remains were first discovered about 100 years ago in Egypt. But unfortunately they were destroyed during World War II after being moved to a museum Munich, Germany.

The idea that Spinosaurus spent a lot of its life in the water wasn't a new notion, as scientists had long suspected that the carnivore could swim, but the new fossils provide more convincing evidence.

"For the very first time, we can piece together the information we have from the drawings of the old skeleton, the fragments of bones, and now this new fossil, and reconstruct this dinosaur," Ibrahim told BBC News.

"All in all, the discoveries by this team show that Spinosaurus is an extremely unusual and specialized carnivorous dinosaur," dino expert Thomas Holtz added to National Geographic.