Researchers develop a method for estimating the body temperatures of long-extinct species, and suggest that dinosaurs operated somewhere between endothermy and exothermy.
The opah, or moonfish, is a deep-sea fish that regulates its body temperature more like a mammal than any of its finned kin, researchers have determined.
Evidence that large dinosaurs had body temperatures similar to modern-day mammals suggests they were either endothermic or extremely good at conserving body heat.