As a human being, is it shameful if we can't outrun a Tyrannosaurus Rex?

If you evaluate it in one sentence

The plot of the Jurassic Park film series

I'm afraid the answer is:

"The T-Rex is chasing me again!"

That's right, the "dinosaur chasing people" in the Jurassic series of movies has always been the most exciting part of the movie. I believe that many viewers will sweat for the protagonist when watching that plot.

If a super predator like Tyrannosaurus Rex really came into being, could we escape its pursuit with just our two legs?

First, let's take a look at how fast the Tyrannosaurus Rex could run. Although the dinosaurs have turned into dry bones, we have no way to test their speed in person, but we can infer their speed based on their bone structure and some similar modern animals.

By comparing the running speed of modern animals, scientists believe that dinosaurs with longer calves and strong muscles of the same size can run faster. By studying the leg bones of dinosaurs, applying the formula of modern animals, and combining the muscles on their tails and other characteristics, it is possible to calculate the running speed of dinosaurs.

Of the more than 1,000 known species of non-avian dinosaurs, the fastest members are Gallimimus and Struthiomimus, which can reach speeds of 60-80 kilometers per hour.

The image of Tyrannosaurus Rex in the documentary "Prehistoric Planet"

Scientists use computers to simulate the running speed of dinosaurs

Image source: Documentary "Natural Evolution"

What about the big star Tyrannosaurus Rex? Scientists have found that the metatarsal bone in the middle of the Tyrannosaurus Rex's foot is significantly thinner near the body and is sandwiched between the metatarsal bones on both sides. This structure is called the symphysis , which can act as a shock absorber when the dinosaur runs at high speed.

Therefore, theoretically speaking, Tyrannosaurus Rex's body has features adapted for high-speed running, but because its body is too large and thick, its speed is still not as fast as that of the light ornithomimids.

Tyrannosaurus Rex's foot has metatarsal structures

Through computer simulation, scientists have concluded that an adult Tyrannosaurus Rex weighing more than 7 tons usually walks at a speed of 4.6 kilometers per hour, which is about the same as our walking speed. When they speed up to catch up with prey, they run at a speed of about 23-34 kilometers per hour, which is similar to the speed of an electric bicycle.

The scene of the Tyrannosaurus Rex chasing the jeep in the movie "Jurassic Park"

In fact, the speed of the Tyrannosaurus Rex can't even catch up with the Jeep

At this speed, it is obviously beyond one's ability to catch up with a jeep like in the Jurassic Park movie.

The average human sprint time for 50 meters is 7-9 seconds, which is about 20-25 kilometers per hour. It can be seen that the speed of Tyrannosaurus Rex is faster than that of ordinary people. The best time of Su Bingtian, known as the "Flying Man of Asia", in 100 meters is 9.83 seconds, and the best time of Bolt, the world record holder, is 9.58 seconds, which is 36 kilometers per hour and 38 kilometers per hour respectively.

So, in front of the top sprinters

Tyrannosaurus Rex still has to admit defeat

In terms of sprinting, Tyrannosaurus Rex is not as good as professional athletes.

But it is still possible to catch up with most humans.

Since it can't outrun professional athletes in short-distance running, how about letting the Tyrannosaurus Rex participate in middle- and long-distance running? After all, the Tyrannosaurus Rex hunts in the mountains every day, so it should be able to win in middle- and long-distance running.

In 2020, a study on the legs of theropod dinosaurs was released. The study found that for small and medium-sized theropod dinosaurs, the longer the legs, the faster they were. For large carnivorous dinosaurs weighing more than 1 ton, their huge bodies have limited their maximum speed. Their long legs are more used to reduce energy consumption during movement so that they can chase prey over long distances.

In other words, the longer the legs of large carnivorous dinosaurs, the better their endurance (when the short legs sprint 100 meters, the long legs only need to walk a few steps, it is obvious who is more tired). Among carnivorous dinosaurs, Tyrannosaurus Rex is definitely the owner of the longest legs. Its legs are more than 3 meters long, which is the best proportion among carnivorous dinosaurs.

What's more, Tyrannosaurus Rex is a member of the coelurosaurs, from which modern birds evolved. Therefore, Tyrannosaurus Rex may have a complete air sac system close to that of birds. The air sacs not only allow dinosaurs to breathe twice, but also take away excess heat from the body when exhaling.

Such a "two-pronged" configuration shows that Tyrannosaurus Rex possessed excellent endurance. They were able to maintain high speeds for a long time, and at least would not be eliminated midway due to exhaustion in middle and long-distance races.

So, what about the speed of human middle and long distance running? The current world record for 400 meters is 43 seconds, 33 kilometers per hour, which is lower than the upper limit of the speed of Tyrannosaurus Rex. From this point of view, it is difficult for humans to outrun Tyrannosaurus Rex in a 400-meter running competition...

A 2020 study found that small carnivorous dinosaurs (such as Compsognathus and Sinornithosaurus) had longer legs and were faster. Large carnivorous dinosaurs (such as Allosaurus and Monster Hunter) had longer legs and better endurance.

The internal organs of Tyrannosaurus Rex are speculated to be composed of air sacs.

You may feel scared after reading this. If you really encounter a Tyrannosaurus Rex, you will definitely not be able to defeat it in a fight, and you will not be able to outrun it even if you run away. Wouldn't that be providing a free lunch for the Tyrannosaurus Rex?

What should we do if we really encounter a Tyrannosaurus Rex? In fact, although the Tyrannosaurus Rex has excellent endurance and is a little faster than us, it has a weakness, that is, its huge body is not as flexible as ours. We can refer to the method of avoiding elephants, using sharp turns and getting into narrow gaps to avoid them.

However, with an adult Tyrannosaurus Rex weighing more than 7 tons, humans are too small a prey for them to make ends meet. There is no need for them to waste their energy on eating us. Instead of hunting us, they might as well go after Triceratops, Edmontosaurus and other more lucrative prey!

Tyrannosaurus Rex preying on Edmontosaurus

Tyrannosaurus Rex may have preferred this more juicy prey than us.

Illustration: Blue Echinops

However, the speeds mentioned above are all about adult Tyrannosaurus Rex. Young Tyrannosaurus Rex are more slender than their parents and are better at hunting small and agile animals, so their speed is quite outstanding.

A young Tyrannosaurus could run up to 50 kilometers per hour - about as fast as a horse. So if we encountered a young Tyrannosaurus, we would be in danger of death.

Based on the morphological differences between adult and young Tyrannosaurus Rex and the study of fossils of Tyrannosaurus Rex and its close relatives, scientists know that Tyrannosaurus Rex lived and hunted in "small families" with clear division of labor. When hunting, young Tyrannosaurus Rex would use their excellent speed to drive prey to the adult dragon or intercept the prey. The adult dinosaur's task was to use its domineering strength and iron beak and steel teeth to make a delicious meal...

Reconstruction of the growth process of Tyrannosaurus Rex

Compared with adult Tyrannosaurus Rex, the young Tyrannosaurus Rex is more slender.

References

The fast and thefrugal: Divergent locomotor strategies drive limb lengthening intheropod dinosaurs

Author: Qianxi Jun

Editor: Dong Xiaoxian

Reviewer: Liu Kun and Li Peiyuan