An up-close experience with incredible speed in the animal kingdom.

These giant felines are the world's fastest land animals. Here's why.

This critter with an extraordinary heartbeat may not be often seen, but the Etruscan shrew is constantly on the hunt for its next meal.

A croc bone locked between the 70-million-year-old predator’s jaws gives scientists a rare look into its life and possibly ...

Life on Earth started out microscopically small, but it didn’t stay that way for long. Here are five of the biggest creatures ...