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Oldest North American Tyrannosaur Discovered: 74 Million Years Old

3/13/2026

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Summary

Story summary

The analysis of a giant shinbone from New Mexico identifies the Hunter Wash tyrannosaur as the oldest known tyrannosaur in North America, dating to about 74 million years ago.
The bone measures about 3.2 feet long and weighs around 4.7 tons, suggesting it was the largest tyrannosaur of its time.
Researchers say more fossils are needed to determine its exact relationship to Tyrannosaurus rex.

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Story summary

The analysis of a giant shinbone from New Mexico identifies the Hunter Wash tyrannosaur as the oldest known tyrannosaur in North America, dating to about 74 million years ago.
The bone measures about 3.2 feet long and weighs around 4.7 tons, suggesting it was the largest tyrannosaur of its time.
Researchers say more fossils are needed to determine its exact relationship to Tyrannosaurus rex.