Chuck Bednar for redOrbit.com – Your Universe Online
An international team of scientists have unearthed a remarkable new type of dinosaur: a species that is not only larger than a Tyrannosaurus rex, but also appears to be the first semiaquatic creature of its kind ever discovered.
The specimen is known as Spinosaurus aegyptiacus, and the newly discovered fossils of this enormous Cretaceous-era predator reveal that it was able to adapt to life in the water approximately 95 million years ago. It was found to have a number of previously unknown aquatic adaptations, including small nostrils that were located farther back on the skull, which would have allowed the creature to breathe while its head was partially submerged.
In addition, the fossils, which were found in the Sahara Desert by paleontologists from the University of Chicago, the Natural History Museum in Italy, the Université Hassan II Casablanca in Morocco and elsewhere, indicate the Spinosaurus measured more than nine feet longer than the largest T. rex specimen ever discovered.
The discovery is the topic of a research paper which was published online Thursday in the journal Science, as well as the cover story of the October edition of National Geographic magazine. The Spinosaurus will also be the subject of a new exhibit opening Friday at the National Geographic Museum, and a National Geographic/NOVA television special airing Wednesday, November 5 at 9pm on PBS.
According to Traci Watson of USA Today, the recently-completed reconstruction of this dinosaur species showed that its skeleton was larger than a fire engine, measuring 50 feet in length. While it was also able to travel on solid ground, making it the largest predator to ever walk the Earth, its natural habitat was in the water.
In addition to its nostrils, the study authors identified several other adaptations which allowed it to live an aquatic lifestyle, including neurovascular openings at the end of the snout similar to those used by alligators and crocodiles to sense movement in water, giant slanted teeth that would have been suited for catching fish, and a long neck and trunk that shifted its center of mass forward to allow it to move around easier in the rivers of its native Africa.
Lead author Dr. Nizar Ibrahim, a paleontologist from the University of Chicago, told BBC News that Spinosaurus was “a really bizarre dinosaur – there’s no real blueprint for it. It has a long neck, a long trunk, a long tail, a 7ft (2m) sail on its back and a snout like a crocodile, and when we look at the body proportions, the animal was clearly not as agile on land as other dinosaurs were, so I think it spent a substantial amount of time in the water.”
The creature was originally discovered in Egypt roughly a century ago and was named Spinosaurus aegyptiacus – “meaning spine lizard of Egypt” – by German scientist Ernst Stromer. However, those bones were destroyed during Allied bombing raids of Munich during World War II, and in the decades that followed, only fossil fragments were able to be recovered.
Image Above: CRETACEOUS LEVIATHAN from the October edition of National Geographic magazine – The only known dinosaur adapted to life in water, Spinosaurus swam the rivers of North Africa a hundred million years ago. The massive predator lived in a region mostly devoid of large, terrestrial plant-eaters, subsisting mainly on huge fish. ART: DAVIDE BONADONNA SOURCES: NIZAR IBRAHIM, UNIVERSITY OF CHICAGO; CRISTIANO DAL SASSO AND SIMONE MAGANUCO, NATURAL HISTORY MUSEUM OF MILAN
According to the University of Chicago, the new Spinosaurus fossils were discovered in the Moroccan Sahara along desert cliffs in a region that had once been a large river system which stretched from modern-day Morocco all the way to Egypt. Of those new fossils, a partial skeleton located by a local fossil hunter wound up being the most important.
The partial skeleton had been taken out of the country and was believed lost, until an exhaustive search finally allowed the researchers to track down the owner of the fossils. Once those remains had been obtained, the investigative team created a digital model of the skeleton thanks to funding from the National Geographic Society, and ultimately created a life-sized 3D replica of the Spinosaurus skeleton.
The digital reconstruction “tells a story of semiaquatic adaptation,” said National Geographic’s Dan Vergano. The creature also possessed powerful forelimbs, curved claws to capture prey, and a small pelvis, short hind legs and muscular thighs that would have helped them paddle in water and differed greatly from land-based dinosaurs.
Spinosaurus also had dense bones designed to help keep them buoyant, enormous skin-covered dorsal spines that would have created a massive sail of sorts on the back of the dinosaur, and feet similar to shorebirds that would have allowed it to stand on or move across soft surfaces. The authors note that it may also have had webbed feet.
“The idea that Spinosaurus was aquatic has been around for some time and this adds some useful new evidence to address that issue,” Professor Paul Barrett of London’s Natural History Museum told BBC News. “But finding a more complete skeleton after the best material was destroyed in a WW2 bombing raid is significant, and this has allowed some surprising things to be found out about this animal.”
“One of the things about this paper that struck me as particularly neat was the suggestion that Spinosaurus was a quadruped – all other meat-eating dinosaurs were bipeds. It would have moved in a really freaky, weird way in comparison with its relatives – whether on land or in water,” he added. “One issue though, due to the way it was obtained – through a private collector – is that it would be good to get confirmation, such as the original excavation map, to show that all of the parts definitely came from a single skeleton.”
Chuck Bednar for redOrbit.com – Your Universe Online