For more than 100 years, researchers assumed that dinosaurs were like giant lizards: sluggish reptiles that spent most of their day basking in the sun. This image changed when we started to realize ...

No, birds are not mammals. Rather, they are avians. Mammals are characterized by their milk glands, hair, vertebrae and their birthing of live young (being viviparous), according to Britannica.

DALLAS (AP) — Scientists once thought of dinosaurs as sluggish, cold-blooded creatures. Then research suggested that some could control their body temperature, but when and how that shift came about ...

Scientists once thought of dinosaurs as sluggish, cold-blooded creatures. Then research suggested that some could control their body temperature, but when and how that shift came about remained a ...

WASHINGTON, May 14 (Reuters) - Move over, mammals and birds, and make room for a fish called the opah in the warm-blooded club. Researchers said in the journal Science on Thursday that this deepwater ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. DALLAS (AP) — Scientists once thought of ...