It is not easy to estimate the speed of an extinct animal and the different estimates may differ according to the calculation method, writes the Italian scientific magazine focus.it.
According to experts, there are two ways to calculate speed.
The first is to compare the speed of today's dinosaur-like animals in size and body conformation.
The second involves the analysis of fossilized tracks by calculating the distance of the tracks it is possible to estimate the speed.
However, for an accurate calculation, it is also necessary to know the length of the feet, and it is not always easy to find fossilized bones near the footprints.

The fastest were bipedal carnivorous dinosaurs with thin legs and a light body.
Among them, ornithomimids (ostrich-like dinosaurs) probably reached 70 km/h.

Slower would have been large herbivorous dinosaurs like stegosaurus, which could at most keep up with a normal walking human (about 6 km/h); large sauropods like Apatosaurus likely moved like modern elephants.

Moreover, according to the latest studies, the structure of Tyrannosaurus rex's legs would not allow it to exceed 40 km/h.
Therefore, the scene from the movie "Jurassic Park" in which the dinosaur reaches a car traveling at 70 km/h, must be redone.