By: Kingsley Wong

New research suggests that the king of the dinosaurs might have been 70% heavier and up to 25% longer than previously believed. The study proposes that the largest Tyrannosaurus rex could have reached an estimated weight of 15 tonnes, compared to the previously thought 8.8 tons, and a length of 15 meters, rather than 12 meters. This indicates that the largest T. rex may have been significantly larger than the current known specimens.

Many of the largest dinosaurs in different groups are represented by only a single well-preserved fossil, making it difficult to determine whether that specimen was an unusually large or small example of its species. Researchers argue that debates about which dinosaur was the biggest, based on limited fossil evidence, may not be very meaningful.

In the new study, Dr. Jordan Mallon of the Canadian Museum of Nature and Dr. David Hone of Queen Mary University of London utilized computer modeling to analyze a population of T. rex. Their approach considered factors including population size, growth rate, lifespan, and the incomplete nature of the fossil record.

Dr. Mallon commented, “Our study indicates that for large fossil animals like T. rex, the fossil record provides little insight into the absolute sizes they may have achieved. While imagining a 15-tonne T. rex is intriguing, the implications are also significant from biomechanical and ecological standpoints.”

Dr. Hone emphasized, “It’s crucial to understand that our study focuses on T. rex, but this issue extends to all dinosaurs and many other fossil species. Debating ‘which is the biggest?’ based on a limited number of skeletons is not very meaningful.”

T. rex was selected for the study due to the extensive information already available about its anatomy. The model used in the research is based on modern alligators, chosen for their large size and close evolutionary relationship with dinosaurs.

The researchers discovered that the largest known T. rex fossils likely represent the 99th percentile, or the top 1% of body size. Their findings, published in the journal Ecology and Evolution, suggest that to find a T. rex in the top 99.99% (a one-in-ten-thousand specimen), scientists would need to continue excavating fossils at the current rate for another 1,000 years.

In conclusion, Dr. Hone’s study highlights that the challenge of determining the absolute size of dinosaurs, like T. rex, is not unique to this species but affects all dinosaurs and many other fossil animals.

The research, using modern alligators as a model, reveals that the largest known T. rex fossils represent only the top 1% of body sizes. The findings, published in Ecology and Evolution, suggest that uncovering a specimen in the top 99.99% would require another millennium of excavation at the current pace. This underscores the limitations of relying on a small number of fossils to make definitive claims about prehistoric sizes. Overall, the study emphasizes the need for more comprehensive data to better understand the true scale of these ancient giants.