Ancient creatures’ metabolisms were more like those of tuna, not birds or reptiles
Dinosaurs weren’t quite like cold-blooded reptiles, but they weren’t like warm-blooded birds either. Instead, they fell smack-dab in the middle.
Comparisons with modern animals reveal that dinosaurs’ metabolisms probably resembled those of great white sharks, researchers report in the June 13 Science.
The findings offer new clues into how the animals lived and also rekindle a longstanding debate. “This paper will make us go back to the drawing board,” says paleobiologist Martin Sander of the University of Bonn in Germany.
For years, paleontologists assumed that dinosaurs most resembled modern reptiles and other cold-blooded creatures — slow-growing, low-energy sluggards that bask in sunlight for heat and don’t need much food. “When I was a kid, dinosaurs were just scaled-up, tail-dragging reptilian brutes,” says paleobiologist