Did dinosaur blood run hot or cold? Both, according to a new study - CNN
![](https://media.cnn.com/api/v1/images/stellar/prod/portrait-dromaeosaur-in-the-snow-by-davide-bonadonna-crop.jpg?c=16x9&q=w_800,c_fill)
Dinosaurs were initially cold-blooded, but global warming 180 million years ago may have triggered the evolution of warm-blooded species, a new study found.
Dinosaurs were initially cold-blooded, but global warming 180 million years ago may have triggered the evolution of warm-blooded species, a new study found.