Tag: Cold-Blooded

ScienceDaily (May 25, 2010) Was Tyrannosaurus rex cold-blooded? Did birds regulate their body temperatures before or after they began to grow feathers? Why would evolution favor warm-bloodedness when it has such a high energy cost?

Questions like these -- about when, why, and how vertebrates stopped relying on external factors to regulate their body temperatures and began heating themselves internally -- have long intrigued scientists.