The tail of a feathered dinosaur has been found perfectly preserved in amber.
The city's future is doomed.
The curious polar-grizzly hybrid known as "pizzly" or "grolar bear" could become much more common as the climate warms.
Mystery of the stone spheres.
Skull surgery performed by our ancestors.
An underwater mushroom.
The largest penguin that has ever lived.
No, it's not a circus trick. This is how Sauteur d'Alfort rabbits actually get around.
The Hawaiian archipelago is amazing geologically. And it's all in the making!
Breathtaking view of Mars' surface.
The largest bird that ever lived was a duck.