A 66-million-year-old tooth reveals T. rex was nearly as warm as a human

Filed by Dr. Vera Quark

Chemical clues preserved inside fossilized T. rex teeth reveal that the dinosaur maintained a body temperature of about 97 degrees Fahrenheit, almost identical to humans. The finding provides direct evidence that the giant predator was warm-blooded, helping explain how it stayed active and survived in chilly environments as far north as Alaska.