The long necked Dreadnoughtus was discovered just last year in Patagonia and pretty much instantly labeled one of the biggest dinosaurs to have ever roamed the Earth. Last summer, it was announced to be the largest that we know of so far. But new research now threatens to take away that title.
A paper published earlier this week, on Tuesday (June 9, 2015), in the journal Biology Letters, suggests that the ancient animal weighed between 30 and 40 tons, rather than 60 tons, as was previously believed due to the size of its leg bones.
The theory sparked controversy among members of the scientific community as the authors used a unique, questionable method of estimating the creature’s weight, leaving experts not involved in the study with more questions than answers.
Karl Bates, lead author and lecturer of musculoskeletal biology at the University of Liverpool in the United Kingdom, gave a statement saying that “Using digital modeling and a data set that took in species, alive and dead, we were able to see that the creature couldn’t be as large as originally estimated”.
For the new study, researchers used mathematical algorithms in order to reconstruct skin volume, then expended it outwards to add muscle, fat and other tissue.
Kenneth Lacovara, a professor of paleontology and geology at Drexel University in Philadelphia and the person who discovered the dinosaur last year, was quick to question Bates’ findings, informing that he and his team are using a non-existant proxy in order to estimate a number that the scientific community can never validate.
Professor Lacovara explained that the researchers in the new study used a model that looked at the dinosaur’s body volume and took it as a proxy for its mass. This is flawed approach as the Dreadnoughtus’ full volume remains unknown for the time being. The fossils that scientist have only make up roughly 45 percent (45%) of the dinosaur’s entire skeleton. In fact, the tail of the fossil is missing entirely, and the head belongs to another specimen.
In addition to this, he finds it hard to believe that one can calculate the volume of a dinosaur’s skin fairly accurately based on the number bones that it has. He adds that artists also vary in how they portray the creatures – some make them look chubby, others make them look as if they were shrink-wrapped.
He stresses that fossils don’t preserve volume, which is what Bates is using, and playfully notes that historically speaking, scientist have used data that existed, which he believes to be pretty good policy.
When Lacovara and his colleagues estimated the animal’s weight, they used a well known scaling method which uses the circumference of the dinosaur’s limb bones.
In his outrage, Professor Lacovara brought forward another very good point – why has this new method only been applied to the Dreadnoughtus? When a scientists develops a new method for doing something, he or she typically applies it to as many species as possible, in particular species that have remains with full skeletons.
The Dreadnoughtus dinosaur lived in present-day Argentina, roughly 84 million to 66 million years ago. Its name loosely translates to “fearer of nothing”, a title inspired by the creature’s size.
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