Oldest Giant Tyrannosaur in North America Found in New Mexico, Hinting at Early T. rex Origins
A 74-million-year-old shinbone from New Mexico reveals the oldest known giant tyrannosaur in North America, likely a close relative of Tyrannosaurus rex and suggesting large tyrannosaurids appeared earlier in the Campanian than previously thought. The bone’s size—about 84% as long and 78% as wide as Sue—gives an estimated mass around 4,700 kg (about 5.2 tons). Researchers note the find may trace Tyrannosaurus origins to southern North America, though more remains are needed to confirm its exact place in the tyrannosaur family tree.