Warm-blooded dinosaurs emerged 180 million years ago

Is it a bird? No. It’s an artist’s concept of a dromaeosaur, nesting in snow. This species of warm-blooded dinosaurs lived during the Cretaceous Period, 145 to 66 million years ago. Image via Davide Bonadonna/ Universidade de Vigo/ UCL.

Warm-blooded dinosaurs were birds’ ancestors

Dinosaurs first came into prominence 230 million years ago. And almost all perished 66 million years ago, when an asteroid crashed to Earth. But, according to the fossil record, some dinosaurs at the time of that...