"Uncovering the Evolutionary Origins of a Giant Tyrannosaur: New Mexico Fossil Reveals Closest Relative to T. rex"

A new study describes a giant tyrannosaurid, named Tyrannosaurus mcraeensis, from the late Campanian—early Maastrichtian of New Mexico, which predates Tyrannosaurus rex by up to 7 million years. The newly discovered specimen, NMMNH P-3698, represents a distinct taxon and is the closest known relative of T. rex, suggesting that giant Tyrannosaurini evolved in southern Laramidia. The study also discusses the differences in morphology between T. mcraeensis and T. rex, as well as the age of the specimen and the implications for the evolution of tyrannosaurid gigantism.