Largest Dinosaur Species: T. Rex Might have been Bigger, Heavier than Previously Thought

The largest dinosaur species to ever roam the earth was the Tyrannosaurus rex or T. rex as it is more commonly known. Recent research indicates that it might even be bigger and heavier than the current records.

The largest T. rex may have weighed as much as 33,000 pounds, or 15,000 kilograms, according to paleontologists from the Canadian Museum of Nature in Ottawa, Ontario.

This makes it heavier than the average school bus, which weighs about 24,000 pounds, or 11,000 kilograms. At the annual conference of the Society of Vertebrate Paleontology (SVP) in Toronto on November 5, the researchers presented their findings.

A specimen known as "Scotty" currently holds the record for being the heaviest T. rex ever discovered. When it was alive, Scotty weighed 19,555 pounds, or 8,870 kg, which is equivalent to 6.5 Volkswagen Beetles.

Dethroning Scotty

The largest T. rex would have been approximately 70% larger than Scotty, according to the most recent research. The discoveries, according to Jordan Mallon, the Canadian Museum of Nature's head of palaeobiology, nearly double the size of T. rex. Mallon is a research scientist and a co-author of the study.

To arrive at this significant conclusion, the scientists first looked at the fossil record, which indicates that roughly 2.5 billion T. rex dinosaurs once roamed the planet. However, only 32 adult fossils, or a very small portion, have ever been found, giving researchers little data to work with, according to The Weather Channel.

To build a model of the largest T. rex possible, Mallon and David Hone, Queen Mary University of London's deputy director of education, also considered population sizes and average life spans. Hone is a co-author of the study and a senior lecturer at the university. When examining variations in body size, they also considered sexual dimorphism, or size differences between animals of the same species.

They ultimately created two models, one with strong dimorphism and the other with zero dimorphisms, according to Mallon. The group disregarded that theory because, if it were accurate, paleontologists would have discovered even larger specimens by this point. If T. rex was dimorphic, they calculate that the dinosaur would have a weight reaching 53,000 pounds or 24,000 kg.

By modeling the T. rex's growth curve over its lifetime using this data, the researchers were able to determine how big an adult of the species might have grown.

Read also: Dinosaur Fossil Found in Mississippi: Looks Like an Ostrich, Tall as a Giraffe 

Elusive Evidence

Mallon stated that the model's conclusions are purely speculative until a T. rex fossil of a size comparable to the one in the model is discovered.

He said that simply put, this is a thought experiment with some numbers. It's entertaining to think about.

The investigation does show how difficult it is for paleontologists to infer information about a dinosaur species from a very scant fossil record.

Thomas Carr, a vertebrate paleontologist from Carthage College, said in an interview with Live Science that this serves as a reminder that, due to the small sample sizes, very little is known about dinosaurs. The recent investigation did not involve Carr. He added that right now, efforts are far short of the required sample size, especially in comparison to other animal species.

Carr, who was present at the SVP conference, added that it is conceivable that T. rex was significantly larger than any individual scientist has discovered thus far.

Carr remarked that it is a truly amazing animal. To picture a T. rex of that size is extraordinary, and he believes a creature that size is statistically possible, Live Science reports.

Related article: Recent Discovery Shows How There Might Actually be Three T-Rex Species