A newly uncovered tyrannosaur leg bone is shaking things up in the dinosaur world. The leg bone uncovered in New Mexico belongs to an unusually large tyrannosaur—the group of dinosaurs that includes the mightyTyrannosaurus rex. The giant leg bone is detailed in a study published today in the journal Scientific Reports. At the time, present-day North America had a subtropical climate and was split in half by a seaway that ran from the Gulf of Mexico north to the Arctic. A Tyrannosaurus rex named Sue at the Field Museum of Natural History in Chicago in 2003.