When a truck passes by, people standing nearby will feel a slight vibration on the ground. This is actually a slight earthquake. When there is an earthquake, there will be seismic waves. More sensitive animals can detect the seismic waves generated by trucks from a distance.
We have reason to believe that those large theropod dinosaurs weighing several tons at every turn, equivalent to the weight of a truck, will make the ground tremble with every step they take. But here comes the problem. For carnivores like Tyrannosaurus (an average weight of 9 tons, equivalent to the load of a medium-sized truck), if they make such a loud vibration when they prey, wouldn’t it be equivalent to warning their prey in advance? Do they have enough time to escape?
A study now shows that the footsteps of Tyrannosaurus rex are smaller than we expected.
A scientist at the University of the Republic of Uruguay analyzed 64 fossil footprints left by large theropod dinosaurs (including Tyrannosaurus rex), and he found that theropod dinosaurs had a more slender foot.
Then, he simulated the seismic waves generated when various dinosaurs, including theropods and non-theropods, step on the ground. He found that the seismic waves generated by the theropod dinosaurs when they stepped on were the weakest in the direction they were moving. In other words, the slender feet of theropods can prevent them from making too much noise when they dive close to their prey, so as not to start the prey from running away.
