Dreadnoughtus, the Mesozoic monster that patrolled Argentina 80 million years ago
by Stephen Brusatte
Some species of dinosaur were astoundingly enormous compared to anything alive on land today, which becomes obvious the moment you stand in the shadow of their skeletons in a museum. This remains one reason why we remain fascinated with these long-extinct beasts.
The colossal size of the long-necked species like Brachiosaurus stretches the limits of our imaginations, and exhausts our vocabulary. And nothing quite gets the hyperbole flowing like the discovery of a gigantic new dinosaur.
So, meet Dreadnoughtus, the 65-ton, 26-metre long plant-eating behemoth from the latest Cretaceous – 84-66 million years ago – found in Argentina. It is named after the World War I British battleship Dreadnought.
This discovery comes only a few months after another team of Argentine researchers reported a slightly older, and apparently even larger, long-necked dinosaur. That discovery dominated the science news for days, to the point where elderly relatives, who never took much of an interest in my career in science, were phoning me up to ask how something so huge could have possibly existed.
Although it may stretch logic, these animals were real. They were living, breathing, evolving organisms that, at least to me, are more fantastic than anything humans have created in legends, myths or even deliberate hoaxes.
But we must be sceptical about such claims. Sometimes palaeontologists are a little too keen to extrapolate, based on limited fossil evidence, and proclaim that the tiny piece of the weathered finger bone they just uncovered came from the biggest, heaviest, fiercest dinosaur to ever live.
In this case, however, our understanding of Dreadnoughtus is not based on a few scraps, but is represented by more than half of the skeleton. Ken Lacovara at Drexel University and his team of palaeontologists found parts of the skull, several vertebrae and ribs, most of the shoulders and forelimb, and much of the pelvis and hindlimb. Their report has been published in Scientific Reports.
This amount of fossil material found is unprecedented for a large long-necked dinosaur. Other contenders for the “biggest dinosaur” crown usually are known from just a few bones. And while we can be confident that these dinosaurs were huge, accurately estimating their weight and length can be difficult. Not so for Dreadnoughtus. We can be very confident that this Mesozoic monster really did weigh about six times as much as an elephant, and was longer than two double-decker buses.
There is an unmistakable wow factor with Dreadnoughtus. It was old, it was huge, it is pretty hard to imagine actually watching one of these things move or eat. But does it mean anything more?
Answering this question will be the next challenge for the impressive team of palaeontologists who described the colossus. Now that we finally have a relatively complete skeleton of a huge long-necked dinosaur, we can start to better understand how these creatures functioned.
These dinosaurs push the limits of what evolution is capable of, and we are only beginning to fathom how they made a living as the largest animals to ever roam the land.
This article was originally published on The Conversation.