Outrunning a T. rex might not have been too hard after all. Depictions of giant dinosaurs sprinting after their prey have been around for decades. But recently, researchers analyzing the creatures’ footprints and skeletons have started to question whether those representations are accurate. Of course, it’s difficult to fully understand an animal’s capabilities from bones and footprints that are at least 65 million years old. But scientists believe they just found a way to settle the question of how fast a T. rex moved: They devised a simple yet remarkably powerful equation which estimates any animal’s maximum running speed based only on its body weight and whether it runs, flies or swims. An animal’s running speed determines everything from its ability to hunt, escape predators, and relocate when the need arises. And yet, through one simple equation (simple for scientists, anyway), researchers have managed to explain 90% of the variation in different animals’ top speeds. And its findings have something to say not only about long-dead animals, but also about humans, and how our species became unique compared to all other creatures. Watch the video above to learn more about the new discovery, and what it says about our own evolutionary backstory.