Seeing a T-Rex come at you can be daunting. Scary. And down right terrifying. Researchers have for years been debating over the speed of dinosaurs, and reconstructions of models have depicted them to be as fast moving creatures.

By the mid twentieth century, that belief has been turned around. Mainly due to large, bipedal theropods like T. rex were often presented standing completely upright, their tails dragging along behind them in a manner suggestive of slow, lumbering locomotion.

The standard model of the T-rex has been revised yet again with some studies claiming that the dinosaur may have been capable of speeds in excess of 45 miles (approx 70km) per hour. According to recent investigations, the T-rex was neither slow or super fast.

According to John R. Hutchinson (who has published studies on T. rex biomechanics in scientific journals no less-esteemed than Nature), the Tyrannosaur likely topped out in a "moderate range" of 5–11 meters per second, or between 15 and 25 miles per hour (24km/h to 40km/h).

This suggest you might be able to outrun it on the low end spectrum. But unless you are Usain Bolt, don't hope to get out of its sight in the long run.