The thought of Tyrannosaurus rex dinosaurs still roaming the Earth would be a terrifying idea. However, according to a new study, if they were still around, we wouldn’t need to run away from them as humans could probably outwalk them.
Based on new analysis of its tail movements, the Tyrannosaurus rex could only walk at a speed of about 3 mph (4.8 km/h). Amazingly, that’s about the same average as a human’s walking speed. It was previously believed that the dinosaur walked at a faster rate of between 4.5 and 6.7 mph (between 7.2 and 10.8 km/h).
Experts focused on the T. rex’s vertical tail movements instead of its legs. Pasha van Bijlert, who is a master’s candidate studying paleo-biomechanics at the Free University of Amsterdam and the lead author of the study, explained this further, “Dinosaur tails were vital to the way they moved around, in multiple ways.” “Not only does it serve as a counter balance, the tail also produces a lot of the required force to move the body forward. It does this through two large tail muscles — the caudofemoral muscles — that pull the legs backwards during each step.”
The dinosaur’s tail would have moved up and down while it walked as well as being passively suspended in the air. Further details were explained by van Bijlert, “This combination — passive suspension while active in locomotion — is unique to dinosaurs; there are no animals alive today with this feature.”
The researchers then had to figure out how large of a step the dinosaur took so they studied the tail of an adult T. rex named “Trix”. “The tail model gives you a likely step frequency/rhythm for T. rex, but you also need to know how much distance it travels with each step,” noted van Bijlert. They calculated that Trix would have had a step length of 6.2 feet (1.9 meters).
Since they have calculated the walking speed of a Tyrannosaurus rex and how large its steps were, the researchers now want to figure out how fast it ran. While it’s been previously suggested that they could run between 10 and 25 mph (between 16 and 40 km/h), the experts will have to take into consideration the dinosaur’s heavy body weight as well as how strong its bones were and the flexibility of its tail as part of their calculations. “We’d also like to apply our method to more species, because that might reveal interesting evolutionary adaptations in the tail’s role in locomotion,” van Bijlert said. The study was published in the journal Royal Society Open Science.
A simulation of a T. rex walking can be viewed here.
In other recent T. rex news, scientists have estimated that about 2.5 billion of these dinosaurs walked the Earth during their 2.5-million-year existence. A different study claimed that they were actually quite social dinosaurs and probably hunted in packs similar to wolves.