Hot-blooded T. rex and cold-blooded Stegosaurus: Chemical clues reveal dinosaur metabolisms

For decades, paleontologists have debated whether dinosaurs were warm-blooded, like modern mammals and birds, or cold-blooded, like modern reptiles. Knowing whether dinosaurs were warm- or cold-blooded could give us hints about how active they were and what their everyday lives were like, but the methods to determine their warm- or cold-bloodedness -- how quickly their metabolisms could turn oxygen into energy -- were inconclusive. But in a new paper in Nature, scientists are unveiling a new...