Newly unveiled fossils indicate a dinosaur known as Spinosaurus aegyptiacus was built to live part of the time in water, according to a report published online for the journal Science.
Measuring 50 feet, making it larger than the Tyrannosaurus rex, Spinosaurus is so named because of the long spines measuring up to seven feet that run down its back and form one large sail.
The dinosaur had an elongated neck, and its hind limbs were smaller and more solid than those of land dinosaurs like the T. rex. and indicate that the Spinosaurus used them to paddle its massive body through the waters.
“The Spinosaurus story is truly unique, it is an international story of scientists getting together and it stretches across a century,” said Professor Paul C. Sereno of the University of Chicago and one of the scientists who has been working on reconstructing the Spinosaurus and its story.
Spinosaurus fossils were first discovered in the Western Desert of Egypt by German paleontologist Ernst Stromer in 1912. The fossils, housed in a museum in Munich, were destroyed in World War II by an Allied air raid, according to National Geographic magazine’s October cover story.
“We’ve been living with more or less a shadow of this dinosaur all of my life,” Sereno said.
The fossils were unearthed by a nomad in Morocco in 1975, sold into the fossil market and wound up in Milan, Italy.
Nizar Ibrahim, a 2014 National Geographic Emerging Explorer and co-author of the Science journal report, recognized the fossils in Italy.
The entire discovery and rediscovery story of the Spinosaurus is the subject of a National Geographic/NOVA special, “Bigger Than T.rex,” which airs on PBS on Nov. 5.
Currently, a life-size model of the Spinosaurus can be seen in an exhibit at the National Geographic Museum in Washington D.C.
Spinosaurus was among the largest predatory dinosaurs to have ever lived and the first known dinosaur adapted for swimming. It lived during the Cretaceous period, about 100 million years ago, in what is now North Africa. The first Spinosaurus fossils were found in Egypt in 1912 and described by German paleontologist Ernst Stromer in 1915. However, that Spinosaurus specimen was destroyed in 1944 during a World War II bombing raid. For many years after the destruction of the fossils, knowledge about Spinosaurus was based solely on Stromer’s detailed drawings, photographs, and descriptions.
It wasn’t until 2008 that scientists got their hands on a new specimen. Paleontologist Nizar Ibrahim was working on his doctorate degree in the Sahara when a local fossil collector approached him with a box of fossil bones that he wanted help identifying. Ibrahim suspected that they might belong to Spinosaurus. A few years later, a museum curator in Italy showed Ibrahim a partial skeleton of Spinosaurus that appeared to match the fossils from the box. Unfortunately, those remains had been donated to the museum and their source was unknown. After much searching, Ibrahim tracked down the fossil collector that he had met in 2008. The man took him to the original site—a cliff in the Tafilalet region of Morocco—where he had found his box of bones. Scientists were able to excavate more remains and ended up with a Spinosaurus skeleton that was about 40 percent complete. Using the new fossils, as well as Stromer’s original drawings and bones from other specimens, they were able to digitally create a complete model of Spinosaurus.
Spinosaurus was about 50 feet long—longer than other known large carnivorous dinosaurs, such as Tyrannosaurus and Giganotosaurus—and its body was long and narrow like a crocodilian. Although North Africa is now mainly desert, the environment was a swampy mangrove when Spinosaurus lived there. The dinosaur was semiaquatic and well adapted for hunting fish. Its skull had nostrils located in the middle, which allowed Spinosaurus to breathe with its head partially submerged in water, and its long snout had holes for nerve channels to sense pressure changes from the motion of prey in water. It had smooth, slanted, cone-like teeth that were ideal for catching fish. Its feet were flat and possibly webbed, which helped them act like paddles in the water. In addition, Spinosaurus had dense bones, similar to penguins, which helped it maintain buoyancy in the water, and short hind limbs.
The name Spinosaurus means “spine lizard.” It had highly distinctive spines on its back: long extensions of its vertebrae that, when covered in skin, may have formed a sail-like structure. The sail of Spinosaurus was likely used as a display to act as a warning to enemies and perhaps to attract mates. Other possible functions for the sail-like structure include storage of fat or regulation of body temperature by shedding heat; however, recent studies have found that the spines had few blood vessels and were unlikely to be wrapped in fat.