If dinossauros were cold-blooded, like today's reptiles, they would have been slow or inactive in cold conditions.

If dinossauros were warm-blooded, like birds and mammals today, they would have benn able to stay warm and active in cold conditions.

Experts once believed that all dinossauros were cold-blooded, but today there is much disagreement.

Some evidence for warm-bloodedness comes from the structure of fossil bones.

The structure of some dinosaur bones is mais like that of warm-blooded creatures than that of reptiles.

Some small meat eaters may have evolved into birds. As birds are warm-blooded, these dinossauros may have been, too.