What? Bigger Than a T. rex?! Well, Science Says It’s Likely!

New Research Suggests Tyrannosaurus rex Might Have Been Even Larger Than Previously Thought

Millennials like me grew up during the release of Jurassic Park, one of the most transformative movies of all time. I can’t name the number of doctors in Paleontology who proudly admit having been drawn to the field after watching the movie. And for a reason, the now classic Blockbuster brought dinosaurs back to life, from scary creatures in science books to everybody’s imagination.

So, of course, we were equally excited when, after some years of movie hiatus, a new saga was released with Jurassic World. With it, they brought a new character to the story, one bigger and scarier than T. rex itelf.

In the movie, Indominous rex is a genetically engineered dinosaur created by combining the DNA of several predatory species, including Tyrannosaurus rex and Velociraptor. Designed to be a major attraction for the park, it turns out to be highly intelligent, incredibly strong, and extremely dangerous, ultimately causing chaos and destruction.

My wife, a paleontologist who loves to give outreach talks to little kids obsessed with prehistoric creatures, didn’t anticipate this (in retrospect, she should have). Suddenly, everyone, including these kiddos’ parents, wanted to know whether such a creature could have been possible.

Of course, there’s a lot to unwrap here, lots of characteristics to evaluate, and the fact that the Dinosauria legacy was abruptly interrupted by mass extinction.

However, I can talk a bit about one aspect of the question. Could they get THAT big?

Recent research by Dr. Jordan Mallon of the Canadian Museum of Nature and Dr. David Hone of Queen Mary University of London examines this question. Their study explores the maximum possible sizes of T. rex and what this means for our understanding of these ancient giants.

Dr. Mallon and Dr. Hone set out to estimate the upper limits of T. rex’s body size by creating a detailed computational model. They used existing data on T. rex’s growth rates, lifespan, and the fossil record’s inherent biases to simulate a population of these dinosaurs.

By factoring in variables like population size and the likelihood of discovering larger specimens, they aimed to understand just how big these dinosaurs could have gotten.

The researchers began by modeling a population of 140 million T. rex specimens based on previous estimates. They used a growth curve to simulate how these dinosaurs might have grown over their lifespans, accounting for both with and without sexual dimorphism (differences in size between males and females).

The model was quite comprehensive, including species survivorship considerations and the biases in the fossil record that affect which specimens are preserved and discovered.

They used data from modern-day alligators to help estimate body size variance, given the similarities in growth patterns and ecological roles.

What did they find?

Well, the study revealed some fascinating insights. The species’ largest known T. rex specimens, like the famous “Sue” and “Scotty,” likely fall within the 99th percentile of body size.

However, the researchers found that the absolute largest T. rex might have been up to 70% more massive than these known specimens, potentially weighing as much as 15 metric tons. To put this in perspective, this hypothetical giant would have been about 25% longer, reaching lengths of up to 15 meters. Spooky!

So, here’s something that may make kiddos and adults happy to learn: despite the awe-inspiring size of these known fossils, Dr. Mallon and Dr. Hone’s work suggests that there were likely even larger T. rex individuals that we haven’t found yet.

“Our study suggests that, for big fossil animals like T. rex, we really have no idea from the fossil record about the absolute sizes they might have reached,” said Dr. Mallon. This implies that the largest individuals were even more colossal than the ones we’ve discovered so far, hidden underground.

Understanding the potential size of T. rex is more than just satisfying our curiosity about “which is the biggest.” It has broader implications for our understanding of dinosaur biology and ecology.

For instance, larger individuals would have had different biomechanical and ecological challenges compared to their smaller counterparts. They would have needed more food, moved differently, and possibly occupied different ecosystem niches. Perhaps one of the reasons we haven’t found them yet.

Dr. Hone emphasized the broader relevance of their findings: “It’s important to stress that this isn’t really about T. rex, it’s the basis of our study, but this issue would apply to all dinosaurs (and lots of other fossil species).”

This means that debates about the largest dinosaurs often overlook the fact that, due to the limitations of the fossil record, we are likely missing the very largest specimens. Maybe Indominous rex large!

This study reminds us of the gaps in our knowledge about the fossil record. While we admire the giant skeletons displayed in museums, the reality is that the largest dinosaurs may have been bigger than the fossils we’ve found. This underscores the importance of continued fossil discoveries and the use of advanced modeling techniques to fill in these gaps.