Earth-shaking dinosaur discovered

Sep 7, 2014

By Sid Perkins

 

A newly identified species of supermassive dinosaur might have been one of the largest creatures ever to walk on land, suggests a study published on 4 September in Scientific Reports1.

Well-preserved bones of the species, Dreadnoughtus schrani, were excavated in southern Argentina between 2005–09. The animal is a titanosaur, one in a typically hefty subgroup of the long-necked, plant-eating dinosaurs known as sauropods.

The genus name Dreadnoughtus, from the Old English meaning ‘fearing nothing’, is a nod to the idea that this dinosaur was so gigantic that healthy adult Dreadnoughtus were probably impervious to attack by predators, says Kenneth Lacovara, a vertebrate palaeontologist at Drexel University in Philadelphia, Pennsylvania, who led the study. The bones of two individuals from the newly described species were found in rocks originally laid down as sediments on a floodplain some time between 66 million years and 84 million years ago.

Roughly 45% of the post-cranial bones of the larger specimen were recovered, Lacovara says. And if researchers use mirror images of bones present on one side of the creature, for example, to stand in for bones missing from the other side, they can produce a fossil reconstruction that includes about 70% of bones in the species’ neck, body and tail.

4 comments on “Earth-shaking dinosaur discovered

  • @OP NATURE link – Although some other titanosaurs have been estimated to weigh as much as 100 tonnes, those figures are based on less-accurate methods extrapolated from fossils that are more fragmentary, says Lacovara. Therefore, he contends that Dreadnoughtus is the largest known land animal for which a body mass can be accurately calculated.

    Moreover, he says, analyses of the larger specimen’s fossils suggest that the creature was not yet fully mature and was still growing when it died.

    The sheer weight of these creatures must have eventually made them very slow moving!



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  • You are quite right, they were indeed VERY slow, being able to do, IIRC, 10kph (at most) on a good day. AFAIR the currently available evidence indicates that these types of dinosaur grew until the day they died.

    But as with African elephants and lions on the savannah, no contemporary predators would have been capable of take one on/down thanks to its sheer size and strength . A swipe from its tail would probably have felt similar to getting smacked with a large telephone pole.



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  • Meanwhile, a prime specimen of another giant has been found!

    Spinosaurus fossil: ‘Giant swimming dinosaur’ unearthed – http://www.bbc.co.uk/news/science-environment-29143096

    A giant fossil, unearthed in the Sahara desert, has given scientists an unprecedented look at the largest-known carnivorous dinosaur: Spinosaurus.

    The 95-million-year-old remains confirm a long-held theory: that this is the first-known swimming dinosaur.

    Scientists say the beast had flat, paddle-like feet and nostrils on top of its crocodilian head that would allow it to submerge with ease.

    The research is published in the journal Science.

    Lead author Nizar Ibrahim, a palaeontologist from the University of Chicago, said: “It is 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.”

    While other ancient creatures, such as the plesiosaur and mosasaur, lived in the water, they are marine reptiles rather than dinosaurs, making Spinosaurus the only-known semi-aquatic dinosaur.

    Spinosaurus aegyptiacus remains were first discovered about 100 years ago in Egypt, and were moved to a museum in Munich, Germany.

    However, they were destroyed during World War II, when an Allied bomb hit the building.

    A few drawings of the fossil survived, but since then only fragments of Spinosaurus bones have been found.

    The new fossil, though, which was extracted from the Kem Kem fossil beds in eastern Morocco by a private collector, has provided scientists with a more detailed look at the dinosaur.

    “For the very first time, we can piece together the information we have from the drawings of the old skeleton, the fragments of bones, and now this new fossil, and reconstruct this dinosaur,” said Dr Ibrahim.

    The team says that Spinosaurus was a fearsome beast.

    The researchers say that, at more than 15m (50ft) from nose to tail, it was potentially the largest of all the carnivorous dinosaurs – bigger even than the mighty Tyrannosaurus rex.

    Scientists had long suspected that the giant could swim, but the new fossil offers yet more evidence for its semi-aquatic existence.

    Dr Ibrahim explained: “The one thing we noticed was that the proportions were really bizarre. The hind limbs were shorter than in other predatory dinosaurs, the foot claws were quite wide and the feet almost paddle shaped.



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