By Will Dunham

WASHINGTON, Dec 4 (Reuters) – Paleontologists for decades debated whether meat-eating dinosaur Nanotyrannus was actually just a juvenile Tyrannosaurus. But within a span of five weeks, the matter seems to have been definitively resolved by two new studies showing that Nanotyrannus was clearly distinct from T. rex.

The latest study, published on Thursday, focused on a throat bone called the hyoid from the first Nanotyrannus fossil ever discovered, a skull unearthed in Montana in 1942. Researchers detected a record of growth in the hyoid – akin to a tree’s annual growth rings – showing that this individual was around 15-18 years old, so either fully grown or nearly so.

This finding follows a study published on October 30 by different researchers that used other bones to est

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