Dinosaur shin bone belongs to a cousin of T. rex

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A study of a dinosaur shin bone unearthed in New Mexico in the 1970s has concluded that it belonged to a close cousin of the Tyrannosaurus rex. The bone is just under a metre long, indicating that it belonged to an animal about half the size of the largest known T. rex, whose size developed relatively late in the evolution of the species. It is also about 74m years old, dating back to the Cretaceous period. This was a time of warm climates and shallow inland seas, when the diversity of dinosaurs was at its peak and the T. rex became an apex predator. The origins of the species have long eluded researchers. One theory holds that it developed in Asia before crossing into North America across a land bridge. But the research supports another hypothesis – that it first lived in North America.