
Some Dinosaurs Were Warm-Blooded Like Modern Birds and Mammals
For decades, dinosaurs were assumed to be cold-blooded like modern reptiles. However, evidence from bone growth rings, feather insulation, and metabolic studies now shows that many dinosaurs — particularly theropods and ornithopods — had elevated metabolic rates and could regulate body temperature. A 2014 study in Science placed dinosaurs metabolically between cold-blooded reptiles and fully warm-blooded mammals.