Enigmatic Dinosaur Skull Sparks Debate over Tyrannosaur Evolution

Researchers say they discovered a new tyrannosaur species that could be the closest relative of Tyrannosaurus rex. The partial skull of this Tyrannosaurus mcraeensis was discovered in 1983 and initially identified as T. rex. The dinosaur was about the same size as T. rex but its skull was longer and more slender, suggesting that it ate different foods. Other scientists point out that T. rex fossils can be very diverse so these differences don’t necessarily indicate that it is a new species. If the identification holds up, it could help to solve the debate over whether giant tyrannosaurs originated in Asia or the Americas.