Tyrannosaurus—the name brings to mind the towering T. rex with its giant teeth and tiny arms, hunting humans in Jurassic Park or standing reconstructed in the natural history museum. This king predator dominates our imaginations, and because of that it is the most heavily studied dinosaur there is. In the last decade, and even in the last year, new studies have shown us that T. rex‘s lineage stretches back to Tyrannosaurus ancestors that stood no taller than us for nearly 100 million years. In the journal Science this week, paleontologists lay out all the recent discoveries that reveal the story of the world’s favorite ancient monster.