Estimating the true size of dinosaurs: new research on T-Rex

New research explores the maximum size of dinosaurs, using the T-Rex as an example, suggesting that the largest specimens may have been much more massive than previously known

Dinosaurs, with their impressive sizes, have always fascinated everyone, from scientists to children. Have you ever wondered how they grew to be so enormous? There’s ongoing debate about which dinosaur was the largest. Most species are known from only a few specimens, making it challenging to determine their true maximum size.

A recent study published in the journal Ecology and Evolution explores the maximum sizes dinosaurs could reach, focusing on the carnivorous Tyrannosaurus rex. Using computer models, Dr. Jordan Mallon from the Canadian Museum of Nature and Dr. David Hone from Queen Mary University of London estimated that the T-Rex could have been 70% heavier than fossil evidence suggests.

Researchers assert that the enormous sizes achieved by many dinosaurs are a never-ending source of fascination, raising questions about how these animals evolved such proportions. There are ongoing debates and counterclaims about which dinosaur species was the largest in its group or even the largest ever.

Most dinosaur species are known from only one or a few specimens, so it is extraordinarily unlikely that the known sizes include the largest individuals that ever existed. Questions remain: How large were the largest individuals? Is there a chance we could find them?

Using computer modeling to estimate T-Rex size

To answer this question, Mallon and Hone used computer models to assess a population of T-Rex, considering variables like population size, growth rate, and lifespan. They chose the T-Rex because it is one of the best-known dinosaurs, with abundant data available.

The researchers found that the largest known T-Rex fossils likely represent only the top 1% of the largest individuals. To find a larger T-Rex, scientists would need to dig for another 1,000 years at the current rate!

The models suggest that the largest possible T-Rex (one in 2.5 billion individuals) could have been 70% heavier than the largest known specimens (33,000 pounds versus 19,400 pounds) and 25% longer (49 feet versus 39 feet).

These figures are model-based estimates, but patterns of discovering giants among modern species indicate that there must have been larger dinosaurs yet to be found, as noted by Dr. Hone:

“Some isolated bones and fragments certainly suggest individuals even larger than those for which we currently have skeletons. It’s important to note that this doesn’t really concern the T-Rex, which is the focus of our study, but this issue would apply to all dinosaurs and many other fossil species. Discussing ‘which is the largest?’ based on a handful of skeletons is not really meaningful.”

This study fuels debates about the largest fossil animals. Many of the largest dinosaurs in various groups are known from a single good specimen, making it impossible to know if that animal was a large or small example of the species. An apparently large species could be based on a single giant individual, and a small species on a particularly tiny individual—neither reflecting the average size of the species.

Dr. Mallon commented on the discovery:

“Our study suggests that, for large fossil animals like the T-Rex, we don’t really have a true idea from the fossil record of the absolute sizes they could have reached. It’s fun to think about a 15-ton T-Rex, but the implications are also interesting from a biomechanical or ecological perspective.”

The chances that paleontologists find the largest individuals ever to exist for a given species are incredibly low. Thus, despite the enormous skeletons displayed in museums worldwide, the largest individuals of these species were likely even bigger than those on display.

ource: Ecology and Evolution