Tyrannosaurus rex was warm-blooded, new study confirms
Contrary to the assumptions of early paleontologists, most dinosaurs weren’t lumbering slowpokes. Centuries of evolutionary reevaluation now indicates the ancestors of present-day birds didn’t simply keep a steady pace—many of them boasted impressive speed. These active lifestyles also forced scientists to reconsider another anatomical detail. Once thought universally cold-blooded, a lot of dinosaurs eventually evolved warmer blood. Thanks to recent technological breakthroughs, paleontologists have finally settled a longtime dinosaur debate: Was Tyrannosaurus rex warm blooded or cold blooded? A study published today in the journal Science Advances settles the debate: The famous “Tyrant king” had an internal temperature surprisingly similar to today’s warm-blooded humans—around 97 degrees Fahrenheit. “No one’s been able to make a temperature measurement like this before,” Robert Eagle, a study co-author and geobiologist at the University of California Los Angeles (UCLA), said in a statement. This places T. rex’s internal temperature ahead of today’s cold-blooded reptiles and even sloths, but short of their avian descendents, which range between 104 and 109 degrees Fahrenheit. Eagle’s team offers the first conclusive chemical proof, but …
