Earth’s biological history stretches far beyond the age of dinosaurs. Hundreds of millions of years ago, prehistoric seas and ...

A new study reveals that the sensitivity of teeth, which makes them zing in a dentist's chair or ache after biting into something cold, can be traced back to the exoskeletons of ancient, armored fish.

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. The sensitive ...