(ORDO NEWS) — The large herbivorous lizards of the Jurassic period did not know how to snap their tail like a whip, but they could still use it as a defensive weapon.
Almost seven years ago, a paper was published in the journal Paleobiology , one of the authors of which was Nathan Myhrvold, a millionaire, former Microsoft CTO and amateur paleontologist.
Several scandals have already been associated with him in the world of paleontology: he collected metal models of dinosaur bodies, and then, on this basis, looked for errors in other people’s scientific papers.
Myhrvold’s co-author was Canadian paleontologist Philip Curry. Myhrvold noticed that the tail of Apatosaurus, a large herbivorous dinosaur from the diplodocid family, resembles a specially shaped shepherd’s whip ( bullwhip ).
It is long and gradually tapers from the handle to the tip. Experiments have shown that the speed with which such a whip cuts through the air in the hands of an experienced shepherd can exceed the speed of sound (it is 343 meters per second).
Having built a computer model, Myhrvold and Curry came to the conclusion that Apatosaurus could also snap its tail at supersonic speeds.
An international group of paleontologists built their computer model and came to completely different conclusions: the tail of Apatosaurus did not reach supersonic speeds. However, he could still move extremely fast.
The main difficulty in modeling the movements of extinct dinosaurs is that paleontologists have only vague and fragmentary information about the soft tissues of ancient giants.
With skeletal remains, things are a little better, but not by much: there is not a single complete set of bones of the same Apatosaurus.
However, several sets of fossils overlap each other’s bottlenecks. Therefore, we can roughly imagine what this representative of a diplodocid looked like, who lived 145-150.7 million years ago.
It weighed 17-23 tons, and the largest specimens reached 72 tons. Like other diplodocids, it had a long neck and an even longer tail.
Scientists have put forward various hypotheses about why this dinosaur has such a tail. Some suggested that the Apatosaurus leaned on it when it stood only on its hind legs.
Others believed that the tail balanced the neck and prevented the animal from falling face first. Still others said that the lizard defended itself with its tail, and the fourth – that it wagged it at supersonic speed during the mating season.
The authors of the new work created a computer model of the tail of Apatosaurus based on data from five sets of fossils.
They got a tail more than 12 meters long and weighing 1446 kilograms. It consists of 82 cylindrical vertebrae, the diameter of which gradually decreases from a fixed base in the region of the femur to the tip.
As the base of the tail moves in an arc, it creates a wave around the entire tail, ending in a whiplash-like loop. You can see how it goes:
The model also took into account the air resistance that the tail overcomes upon impact. It turned out that the maximum speed that it develops is 32.7 meters per second (118 kilometers per hour), which is more than ten times lower than the speed of sound.
The result of the new work differs so much from Myhrvold’s simulation because its authors took into account a fixed base to which the tail was attached.
But even if you add the movement of the hip, the speed of the tail does not increase much. We are no longer talking about any “supersonic tail”.
In addition, the authors of the new study tested whether the tail of a living dinosaur could even withstand the load of supersonic speeds.
They entered the parameters of three soft tissues: skin, joints and ligaments. Calculations were made for human, buffalo, pig and crocodile tissues.
It turned out that when the tail-whip moves, the very first skin is destroyed – it becomes incredibly fragile along its entire length.
Later ligaments and joints suffer. The tail of a living dinosaur, not an iron one, would not have lasted long, so the owner would hardly have used it like that.
The new findings suggest that Apatosaurus’ tails could not have traveled at supersonic speeds. However, the authors suggest that diplodocids could still beat their tails fast enough to be used as a defensive weapon or for intraspecific fighting during the mating season.
Blows delivered at a speed of more than 30 meters per second are quite painful for the enemy, but do not injure the owner of the tail.
Contact us: [email protected]