We thought Tyrannosaurus rexes were huge. We now have reason to believe that they were 70% even bigger.

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A few years ago, in August 1991a group of archaeologists unearthed in Saskatchewan, Canada, a mass of bones of what appeared to be a dinosaur that had lived at late cretaceous. The discovery excited them so much that it is said that that same night the expedition celebrated it by toasting it with a good Scotch whiskey. In a nod to that celebration today the prehistoric creature is known inside and outside of Canada as “Scottie”.

They had reasons to do so: the vestiges of the Frenchman River valley belonged, as it would be verified years later, in 2019, to the Tyrannosaurus rex (T-rex). largest ever discovered.

Coming to that conclusion took time because Scotty’s bones were encased in hard sandstone, which lengthened the painstaking labor of removing the stones, assembling all the remains, and then studying them against other similar fossils. The effort was considerable, but it was worth it. Before the archaeologists it took shape “the rex of rexes”What joked back in the day Soctt Persona researcher in the Department of Biological Sciences at the University of Alberta.

Puns aside, Scotty certainly stood out for his enormous dimensions.

Studies revealed that when roaming the valleys of what is now Saskatchewan, the old T-rex weighed about 8,870kgconsiderably more than an african elephant, and was 12 meters long. Seen in the museum could be fascinating. Standing before its open jaws 66 million years ago, however, was an experience that few creatures wanted to live.

What if Scotty was meh?

Now, three decades after Scotty’s find, we have indications that while Canada’s T-rex was huge, at least by the standards we’re used to dealing with, it might not be so huge among its peers. What’s more, the calculations with the information we handle today have allowed us to ask ourselves a question that points in a very different direction: What if that Scotty who has been fascinating us for years —and terrifying us— Was it really a normal T-rex, far, far away from the enormous dimensions reached by other specimens?

That is the question that a team of experts has launched during the annual conference of the Vertebrate Paleontology Society in Toronto. During the meeting, Jordan Mallon, a researcher at the Canadian Museum of Natureand David Hone, from Queen Mary University of London, presented a theoretical exercise which has led to a fascinating conclusion: T-rexes could have reached dimensions much larger than we previously believed.

His estimates point specifically to the fact that the largest T-rex could reach the 15,000 kilograms, much more than a school bus of 11,000 kilos. The data would be 70% more than what the fossils we handle and what the bones of old Scotty tell us suggest. “That almost doubles the size of T-rex.” mallon explained to the journal Live Science.

The big lie we had told ourselves about the Tyrannosaurus rex: it was not one species but three different ones

For their calculations, the scientists started from the fossil record and a striking fact: it is estimated that they came to walk on Earth 2.5 billion Tyrannosaurus Rex, a more than considerable number of specimens that moved during 127,000 generations. Despite this number, the reality is that we only handle a few dozen adult fossils: 32, to be more precise, according to calculations published in 2021 in Nature. The data is equivalent to only one in 80 million T-rex. Little bit. Very little. And, of course, that limits our own ability to know them.

Mallon and Hone built on that foundation and analyzed population numbers and average lifespans to create a model of a T-rex. “as big as possible”, according to Live Science.

During their research they took into account possible variations based on sexual dimorphism, the phenomenon that explains why lions and lionesses or roosters and hens are so different. Taking this factor into account and assuming that the Tyrannosaurus rex was dimorphic, his model indicated that it could reach 24,000 kilograms, a possibility that they ended up ruling out because —Mallon acknowledges— if it were true, scientists would have already found larger individuals.

The other model, without dimorphism, did allow them to model a growth curve throughout the life of the dinosaur and estimate what dimensions it could have reached as an adult. The team acknowledges in any case that for the moment, and while waiting to unearth fossils that corroborate their calculations, what they are dealing with is only “a thought experiment with some numbers behind”.

“This reminds us that what we know about dinosaurs is not much, since the sample sizes are very small,” Thomas Carr, a scientist at Carthage College, who was not involved in the research but did attend the WoerdsSidekick website, acknowledges. the lecture given during the day of the Vertebrate Paleontology Society (SPV): “Right now, we are nowhere near the sample size needed, especially when compared to other species.”

Cover image: Jon Butterworth (Unsplash)

A few years ago, in August 1991a group of archaeologists unearthed in Saskatchewan, Canada, a mass of bones of what…

A few years ago, in August 1991a group of archaeologists unearthed in Saskatchewan, Canada, a mass of bones of what…

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