T-Rex has a reputation as a vicious, powerful predator that was feared across the prehistoric world it inhabited. People generally imagine Tyrannosaurus Rex the way it is portrayed in Jurrasic Park, but the truth seems to be different—a team of Dutch scientists proved that T-Rex walked around 4.6 km/h, just like Homo Sapiens.
Four meters tall, 12 meters long, and weighing up to nine tons, T-Rex has always been interesting for researchers all over the world. However, no studies considered the tail to be a factor in the overall movement of the T-Rex. This proved to be a major oversight, given that the tail itself accounted for more than 50% of its body weight.
It is important to note that both animals and people use walking in order to save energy—moving around by running was a preferred means of movement during hunting or escaping danger. In the same way people achieve the optimal walking speed by swinging their arms, T-Rex did with its tail since its front limbs were too short to be used for this.
The team involved in the study made a 3D digital model of a T-Rex based on a skeleton of a female excavated in the US, whose remains were dated to be 66-million-years-old. After doing so, they added muscles and ligaments which would naturally correspond to vertebrae of the skeleton, subjecting it to a series of tests.
By combining the results of the tests, and taking into account factors such as the height of hips and tail movement frequency, the team was able to come to a conclusion that an average step of a T-Rex was 1.94 m. Although it sounds like a lot, T-Rex was moving very slowly due to its size so it walked some 4.6 km an hour, on average.
We know T-Rex was a vicious carnivore, so the main question remains—how fast could T-Rex run when hunting? According to this study, between 20 and 30 kilometers per hour. While there are researchers who claim it was over 30 km/h, the lead author claims that this would almost certainly result in broken limbs in T-Rex, which would have been lethal.