News Animals

Dinosaur debate gets cooking

Researchers deflate evidence for cold-blooded dinosaurs

By Meghan Rosen

- More than 2 years ago

Life stories written in mammal bones are being used to debunk a key argument for cold-bloodedness in dinosaurs.

LINES OF EVIDENCE Just as in dinosaur fossils, thin, dark growth lines cut across the bones of mammals (European red deer shown). The finding refutes a key argument that dinosaurs were cold-blooded. Courtesy of Meike Köhler

Annual growth lines etched in the femurs of 115 wild warm-blooded mammals such as giraffes, reindeer and gazelles are similar to those previously seen in the bones of dinosaurs and other reptiles, researchers report online June 27 in Nature.