Spinosaurus was the largest predatory dinosaur ever found. The species was first discovered a century ago, but it is only recently that the true nature of the ancient animal has been understood.

Spinosaurus aegyptiacus was a semi-aquatic animal, stretching 50 feet from head to tail. These mighty hunters regularly tracked down and killed sharks, in addition to a wide range of other marine animals. The ancient creatures sported a distinctive sail on their backs.

Paul Sereno, a paleontologist from the University of Chicago, held a press conference to announce the results of the study. The researcher is describing the species as half duck and half crocodile. The species is now revealed to be the first water-adapted non-avian dinosaur ever discovered.

Spinosaurus was reconstructed, in full, using newly-discovered fossils. Newly-revealed information from Ernst Stromer, the paleontologist who first discovered the species, was also utilized in the re-construction.

The body construction of the ancient animal included paddles, a snout set back far on the head to allow breathing while partially submerged under water. Hip and leg bones were smaller than those seen in other species of Spinosaurus, suggesting the creatures may have spent significant time in water. Cone-shaped teeth, set in a slender jaw, allowed the ancient predators to capture prey in the marine environment.

"The animal we are resurrecting is so bizarre that it is going to force dinosaur experts to rethink many things they thought they knew about dinosaurs," Nizar Ibrahim, a vertebrate paleontologist at the University of Chicago, and leader of the new study, said.

The dinosaur lived roughly 97 million years ago, in an African river system.

Spinosaurus was larger than any other carnivorous dinosaur, including the fearsome Tyrannosaurus rex. Just the sail of the creature stodd taller than a full-grown human being.

Stromer discovered the first Spinosaurus in Egypt in 1915, and the paleontologist immediately published descriptions and illustrations of his find. The entire collection was destroyed in an Allied bombing raid of Munich in April 1944.

Other Spinosaurus fossils were discovered after the destruction of the original collection. However, none of the later finds were as complete and detailed as the artifacts collected by Stromer.

Ibrahim was returning from a dig with his team in 2008 when they stopped in a small desert town. There, a resident brought the paleontologist a box containing bones and dirt, including a long, rib-shaped artifact, marked by a red line. The researcher later saw a similar mark in bones presented to him while visiting a museum in Milan. No one knew where the bones were collected, leading Ibrahim on a quest to once again find the man who provided him with the original sample. Once the location was known, a wealth of new fossils of the species were found.

Study of Spinosaurus aegyptiacus was detailed in the journal Science.