You could run faster than one T. rex? According to new research, you may be able to overcome one by walking.
In the movie “Jurassic Park” (Warner Bros., 1993), a panting of terrified people tries to escape the famous T. rex, but science quickly cast a shadow over the film’s beast and proved that the king of tyrannosaurs would not have been fast enough to run a jeep. Now, researchers have slowed the sea dinosaur even more.
New simulations based on tail movement have shown that T. rex it wasn’t even a quick walk. In fact, his preferred speed was below 5 km / h, about half the speed of previous estimates. To put this in perspective, it’s about the average walking speed for a man, right British Heart Foundation.
Related: Image gallery: His life T. rex
Tyrannosaurus rex, the largest carnivorous dinosaur, lived in what is now the western United States, from about 66 million to 68 million years ago, until the end Cretaceous period, and probably numbered in the billions.
An adult T. rex it would have measured about 40 feet (12 meters) long, was 12 feet (3.6 m) tall, and weighed an average of about 5,000 to 7,000 kilograms (5,000 to 7,000 kilograms), according to American Museum of Natural History in New York. The hardest known T. rex, a strong specimen found in Saskatchewan, Canada, and nicknamed “Scotty”, weighed 8,870 kg for 19,555 pounds, Live Science previously reported.
But how fast could such a large animal move? Previously, researchers answered this question about T. rexthe height of the mass and the hip, which sometimes incorporates the length of the step from the preserved paths. These estimates place a T. rexwalking speed is between 4.5 and 6.7 mph (7.2 and 10.8 km / h), about as fast as a mediocre human runner.
For the new investigation, rather than focus on T. rexThe scientists instead explored the role played by the vertical movement of the tyrannosaurus’s tail, said Pasha van Bijlert, a master’s candidate studying paleo-biomechanics at the Free University of Amsterdam and lead author of the new study on T. rex walking speed.
“Dinosaur tails have been vital to the way they have moved, in many ways,” van Bijlert told Live Science in an email. “Not only does it serve as a counterbalance, the tail also produces much of the force needed to move the body forward. It does this through two large muscles of the tail – the caudofemoral muscles – that pull the legs back during each step. ”
Passive and active
Bipedal (two-legged) T. rex, the tail would have been passively suspended in the air, but also actively engaged and swaying naturally up and down while walking. “This combination – passive suspension while active in locomotion – is unique to dinosaurs; there are no animals alive today with this characteristic,” van Bijlert explained. “Because of this, we were extremely intrigued by his role in the way T. rex he would have walked. “
That T. rex the tail swings, stores and releases energy through stretched ligaments. When the rhythm of an oscillating tail reaches resonance – “the greatest movement response with the least effort” – that rhythm is known as the “natural frequency” of the tail, said van Bijlert. The natural frequency in a T. rex the tail would then indicate the frequency of the animal’s pace while walking without haste, the researchers wrote in the new study, published online on April 21 in the journal Royal Society Open Science.
Related: In pictures: A new look at T. rex and his relatives
Standing as a model for researchers T. rex was an adult specimen known as the “Trix” in the collection of the Naturalis Biodiversity Center in Leiden, the Netherlands. The study authors scanned and modeled the bones of the Trix tail, referring to marks on well-preserved vertebrae that showed where the ligaments were attached. From this digital reconstruction of the bone and ligament, they created a biomechanical model of the tail.
“The queue pattern gives you a probable frequency / pace for the step T. rex“But you also need to know how far you go with each step,” said van Bijlert. To find out, the scientists took the length of a tyrannosaurus that was slightly smaller than the Trix, scaling it to the size of the Trix that the length of the Trix step would be 1.9 m (6.2 feet), then calculated the walking speed by multiplying the step frequency by the step length.
“Our basic model had a preferred speed of 2.86 mph [4.6 km/h]”Which was significantly slower than previous estimates of walking speed,” Van Bijlert said in the email. Depending on some of the assumptions about ligaments and how the vertebrae rotate, you get slightly lower or faster speeds (1.79 to 3.67 mph) [2.88 to 5.9 km/h]), but everywhere, they are all slower than previous estimates, “he said.
Covering new ground
However, there is still some uncertainty in this area, as it focuses on the up and down movements of the tail, “and the muscles – as well as the lateral movements – are not taken into account,” said John Hutchinson, professor of biomechanical evolution. at Royal Veterinary College in Hertfordshire, UK, said for Live Science in an email.
“No one in their right mind thought that dinosaurs had perfectly rigid tails (up / down or side / side), but it was a neglected subject for locomotion,” said Hutchinson, who was not involved in the new research. “So this study covers new ground in a smart way, with an original model.”
The new estimate also reflects “a strong emphasis on elastic storage,” the study’s authors wrote, and the storage capacity of tyrannosaur tails could be lower than the model suggests, Hutchinson added. However, this flexible queue model “would be useful to integrate and compare with other approaches in the future,” he said.
How about T. rexNext steps, study authors want to incorporate flexible tail into running models T. rex, said van Bijlert. Maximum operating speed for a T. rex it is believed to be between 16 and 40 km / h between 10 and 25 mph, according to Hutchinson. Biomechanical researchers have long proposed this T. rexThe maximum speed of operation would be limited by the strength of his bones, because the animal was so heavy. However, a flexible tail could change this by acting as a shock absorber while running, “allowing it to run faster without breaking its bones,” said van Bijlert.
“We would also like to apply our method to more species, as this could reveal interesting evolutionary adaptations in the role of the tail in locomotion,” he added.
Originally published on Live Science.