- Tail wagging was employed by dinosaurs to help with their angular momentum
- This theory explains how ballerinas and figure skaters can execute pirates
- It is also similar to how humans move their arms back and forth during movement
A new study shows that T.Rex and other dinosaurs swung their tails from side to side while running, in much the same way that humans swing their arms during movement.
This tail wagging was to help with angular momentum—a principle that determines how human ballerinas and figure skaters execute pirates today.
Tail wagging was a feature not only of Tyrannosaurus, but also of other bipedal dinosaurs, including the agile Coelophysis and the intelligent and ferocious Velociraptor.
Despite being separated by more than 300 million years of evolution, the study shows an impressive biomechanical link between dinosaurs and humans.
Researchers claim this could help inform more precise animation in future dinosaur films and documentaries, such as in future installations in the ‘Jurassic Park’ franchise.
Pictured, annotation from researchers of Coelophysis, a bipedal dinosaur that lived about 221.5 to 196 million years ago. Tail wagging was employed to help with angular momentum—a principle that determined how ballerinas and figure skaters could execute pirates.
Like other dinosaurs, Tyrannosaurus rex (T.Rex, pictured) was bipedal—meaning it walked on two legs.
What was T. Rex?
Tyrannosaurus rex was a species of bird-like, meat-eating dinosaur.
It lived in the western part of North America 68-66 million years ago.
They can reach 40 feet (12 m) long and 12 feet (4 m) long.
More than 50 fossil specimens of T.Rex have been collected to date.
The monstrous beast had one of the strongest bites in the animal kingdom.
T.Rex. an artist’s impression of
The study was carried out by the Royal Veterinary College (RVC) as well as paleontologists, biomechanists and engineers from the UK, including Australia, Belgium and the US.
Using computer simulations and new methods developed by engineers working in medicine and aeronautics, the team assessed the running biomechanics in dinosaurs with the tail, to move the two hind legs.
“I was very surprised when I first saw the simulation results,” said lead author Dr. Peter Bishop, a former postdoctoral researcher at RVC and currently a research fellow at Harvard University.
‘After running a barrage of further simulations, including a model with a heavy tail, a model with a light tail and a model without a tail, we were able to demonstrate that tail wagging was a means of controlling angular momentum throughout the gait.’
Researchers modeled a small carnivorous dinosaur, Coelophysis, a 210-million-year-old theropod that weighed about 15 kilograms.
These simulations of theropods produced speeds of 6.65 meters per second, or about 15 miles per hour—a fast race for the average person—supporting previous studies that Coelophysis was a nimble dinosaur.
‘More surprising is that the apparent side-to-side swing of the tail was synchronized with the back-and-forth swing of its long hind limbs,’ RVC said.
‘Swinging from side to side, the tail of a bipedal dinosaur was the main regulator of angular momentum, helping to dynamically counterbalance the motion of other body parts, such as the hind limbs.’
As in humans, this ‘control’ of angular momentum helps to make movement more economical and stable.
This illustration shows the difference between the extinct Coelophysis dinosaur (right) and the modern-day Tinmau bird (left)
Coelophysis (bottom) and Tinamou (above) did not proceed in the same way. But subsequent simulations showed that the team’s simulations worked well enough for a live bird.
Next, the team simulated walking and running in a modern South American tinamou bird (Eudromia elegans), which weighs about 500 grams.
While the extinct Coelophysis and extant tinamou did not proceed in the same way, tinamou simulations accurately replicated important aspects of walking and running.
Co-author Dr John Hutchinson, Professor of Evolutionary Biomechanics at the RVC, told MailOnline: “Tinmau showed that the simulation worked sufficiently well for a living bird where we can learn about how the animal should behave. I know more.”
‘So that led to confidence in using simulations to estimate how extinct dinosaurs ran.
‘We think the findings should apply to many other bipedal dinosaurs with large tails. T. rex would be a good example.’
Velociraptor, or commonly known as ‘Raptor’ (pictured here in artist’s impression), was intelligent, ferocious and a skilled hunter.
Until now, studies have always treated the tail of non-bird dinosaurs as a stable, posterior extension of the pelvis, which acts as a counterbalance.
However, this new study published in the journal science advanceIts importance and previously unrecognized role, ‘mechanically demonstrates’.
“These state-of-the-art three-dimensional simulations show that we still have a lot to learn about dinosaurs,” Hutchinson said.
‘Our results raise interesting questions about how dinosaur tails were used in a full range of behaviours, not just including locomotion, and how these functions evolved.’
Previous research published this year showed that T.Rex was only able to crush the bone of its unfortunate victim thanks to its rigid lower jaw.
Scientists previously assumed that the T.Rex had a flexible jaw similar to that of a snake to keep its prey from battling, but analysis showed that the lower jaw was kept flat and strong.
Another study reported that T. rex enjoyed a ‘comfortable’ walk at only 2.8 mph – lower than previous estimates and similar to the natural walking speed of humans and other modern animals.
The T.REX enjoyed a leisurely stroll at just 2.8MPH, analysis of their tails shows
Scary Tyrannosaurus Rex…