The New Dinosaurs

Already, 2014 has proven to be a golden year for paleontology, with several newly unearthed species having been revealed over the past few months. These include the small, feathered Kulindadromeus zabaikalicus, of which we wrote of earlier this year, whose discovery has many scientists believing that almost all dinosaurs may have had some form of feathers. Yet besides K. zabakikalicus, there are many more dinosaur discoveries this year that have caused us to become excited. Here are some new members of the dinosaur family that interests us the most:

The first is Rukwatitan bisepultus, a Titanosaur- a massive form of dinosaur, not too unlike in appearance to the Apatosaurus of Jurassic Park fame, which emerged during the final few million years of the Cretaceous period. While some Titanosaurs weighed only as much as a cow, others were as massive as several elephants combined, making them some of the largest animals to ever walk on land.

Artist’s rendition of Rukwatitan bisepultus
Image Credit: Mark Witton / University of Portsmouth

What makes Rukwatitan bisepultus interesting is that, unlike most Titanosaurs, it wasn’t found in South America, which has boasted some thirty separate Titanosaur discoveries, mostly within the continent’s mountainous Patagonia region in the southern Andres. Rather, Rukwatitan was discovered across the Atlantic Ocean, in western Africa, a continent in which, to date, only four Titanosaur species have been discovered. Dating back some 100 million years, Rukwatitan , which was found in Tanzania, together with another Titanosaur fossil found in Malawi, Malawisaurus dixeyi, show distinct differences both from their South American and Northern African counterparts, suggesting that Titanosaurs found in modern sub-Saharan African were separated from their cousins by geographic barriers such as mountains or deserts during their evolution. Although Rukwatitan was not quite as big as some other Titanosaur species, it was still no wimp, with forelimbs over six and a half feet long- taller than a full-grown man.

As large as Rukwatitan bisepultus was, however, it was nothing compared to its cousin discovered across the Atlantic Ocean. Also a Titanosaur, Dreadnoughtus schrani, whose name means “fear nothing”, was 85 feet long and a massive 65 tons, as much as a dozen elephants or seven T. rex fossils. In fact, Dreadnoughtus was so huge that its mass was greater than a modern Boeing 737-900 Airliner, with a few tons to spare.And it could have been larger. When scientists began studying Dreadnoughtus’ fossilized remains, they found signs to suggest that the dinosaur wasn’t yet fully grown, and could have reached sizes even greater than it’s already gargantuan proportions. Because of how huge it was, Dreadnoughtus would have had to spend its entire waking life eating, moving from tree to tree throughout the course of the day to consume enough energy to survive.

Although fragments of other potentially larger dinosaurs have been discovered, Dreadnoughtus is significant in how well it was preserved. Some 70% of Dreadnougtus’ skeleton remains intact, which makes it the best preserved Titanosaur skeleton ever discovered- making it as the largest dinosaur whose size has been accurately measured.

And then there is Spinosaurus aegyptiacus, the largest of all carnivorous dinosaurs. Sporting a giant “sail” on its back that lends credit to its name, Spinosaurus was some 10 meters long, 3 meters longer than T. rex. Yet, unlike T. rex, Spinosaurus didn’t only hunt on land. If scientists are correct, this massive carnivore could be the first semi-aquatic dinosaur ever discovered.

Several features of Spinosaurus have drawn scientists to this conclusion. For one, there is the placement of its nostrils, which are in the middle of Spinosaurus’ crocodile-like snout and would allow it to breathe while most of its head was submerged. And then there are its interlocking, conical, slanted teeth, which along with Spinosaurs’ curved claws made Spinosaurus particularly adapted for catching fish. Yet most telling of all is in Spinosaurus’ long neck, which would have shifted its center of mass so far forward that it would have prevented it from walking on two limbs on land, forcing it to crawl on four limbs instead. However, this particular bodily arrangement would have also made it easier to move about in water.

As opposed to Dreadnoughtus or Rukwatitan, Spinosaurus was not in fact discovered in recent months. Rather, it was rediscovered after its initial skeleton, uncovered in the early 20^th century, was destroyed during a British Air Force raid on Munich. For over half a century, all scientists knew about this creature came from the drawings that survived the Second World War. In finding a new, more complete skeleton, scientists are now able to discover more about this strange carnivore than they ever could before- resulting in findings such as its bizarre semi-aquatic nature.