Shark-eating dino discovered

Spinosaurus had a long neck, strong clawed forearms, powerful jaws and the dense bones of a penguin. It propelled itself in water with flat feet that were probably webbed, according to a study released Thursday by the US journal Science.

The beast sported a spiny sail on its back that was 7 feet (2 meters) tall when it lived 95 million years ago - and it was big enough to pose a serious threat to local sharks.

The ancient reptile, technically known as Spinosaurus aegyptiacus, was already known to scientists from a long-ago fossil discovery, but most of those bones were destroyed in Germany during World War II.

Long tail, narrow hips, paddle feet

New bones, from the predator's skull, vertebra, pelvis and limbs were found last year along an old riverbank in the Sahara desert, in the Kem Kem beds of eastern Morocco.

The discovery was a boon to paleontologists, who have had little to study when it came to Spinosaurus.

Its long tail, narrow hips and paddle-shaped feet likely helped the 50-foot-long (15-meter) creature move through the water with ease, experts said.

Spinosaurus also had dense bones to help control its buoyancy in water, and a long snout with high-set nostrils that could allow easy breathing while partially submerged.

"Taken together, these features strongly suggest that Spinosaurus was the first dinosaur that spent a significant amount of time in the water," said lead author Nizar Ibrahim, a paleontologist at the University of Chicago.

But not all experts are convinced that the latest findings show that Spinosaurus was a swimmer.

Ken Carpenter, director of paleontology at the Prehistoric Museum in Price, Utah, said the waters in the region might not have been deep enough for it to truly swim.

"The rivers in the land of Spinosaurus were small and undoubtedly shallow (hip deep at most)," Carpenter told news agency AFP. "As for the anatomical evidence, there are lots of alternative hypotheses to explain the oddities."

bk/jm (AFP, AP)