The Largest T. Rex Discovered Is Nearly 70% Larger Than Previously Believed

The Tyrannosaurus rex was one of the most terrifyingly large creatures to walk the Earth 65 million years ago (via the American Museum of Natural History). According to Britannica, the average adult T. rex may have weighed around 9,000 to 15,000 pounds. But newer research by paleontologists from the Canadian Museum of Nature estimate that the largest known Tyrannosaurus rex fossil could have been 70% larger than the previous estimate, bringing into question how large the average T. rex really was.

Jordan Mallon, co-author of the study outlining this discovery, claims that if measurements from this study are correct, the average size of a T. rex could have been double what was previously known (via Live Science). Unfortunately, with only 32 adult Tyrannosaurus rex fossils having been discovered so far, there is limited data to work with, according to Nature. This new research may help scientists better understand just how large these creatures really were, but gaps in our understanding still exist due to the small sample size of fossils. 

The largest t. rex fossil found was massive during its lifetime

Before the research team from the Canadian Museum of Nature made their discovery, the record-holding T. rex was still an impressive specimen. According to Smithsonian Magazine, the specimen, nicknamed "Scotty," would have weighed an estimated 19,555 pounds when it was alive. Not only that, but the researchers that studied Scotty found that this T. rex was also one of the longest-lived T. rex specimens found so far, likely living into its early 30s (via The Anatomical Record).

According to National Geographic, Scotty was found in 1991 at a fossil site in Canada. The T. rex fossil was almost 65% complete, allowing researchers to take a detailed look at its life. Researchers studying Scotty's fossilized remains stated that the "relative scarcity of other equally large and mature T. rex specimens" means that these beasts may only be able to reach sizes up to eight tons (via Live Science). That was until the most recent findings put Scotty's size at a much higher number than before.

Researchers built models to estimate the massive t. rex's size

The goal of the paleontologists at the Canadian Museum of Nature was to estimate the average size of a living Tyrannosaurus rex by building models that demonstrated its growth curve as it aged. This involved a more detailed look than previous estimates, which were calculated using only the size of the bones present and what we understood about the king of the dinosaurs at the time (via the American Association for Anatomy). If correct, the estimates of the growth curve put Scotty's actual weight 70% higher than previous estimates.

According to study co-author Mallon, it is important to keep in mind that there are not enough specimens that have been discovered yet to definitively say what the average T. rex size would have been: "This is simply a thought experiment with some numbers behind it. It's something that's fun to think about" (via Live Science). This research serves as a reminder that our knowledge on prehistoric creatures is very limited, yet new discoveries can lead to new analysis.