110 million years ago, a lush river flowed through the heart of what is now a desert in Africa. Lurking in the depths of the river, a humungous monster waited for its prey to come to the river's edge to drink…and to die. More than 40 feet long, this giant ancestor of the crocodile stalked and killed dinosaurs. In 1997, dinosaur hunter Paul Sereno discovered the enormous reptile fossil named SuperCroc. Learn how modern science uncovers the ancient...

Read about the famous experiment in electricity and its importance.

In the ocean, a box jellyfish dangles tentacles covered with venom-filled stingers. The jellyfish uses its stingers to kill its prey. But its venom can also kill humans within minutes. The brightly colored poison dart frog is deadly to humans too. Just a speck of its poison can kill a person. These two creatures are among the most venomous and poisonous animals in the world. How do animals use their poisons? When are humans in danger?

Whooping cranes once lived all over North America. But by the 1940s, only one tiny flock was left. These beautiful birds were in danger of dying out. Scientists decided to start a second flock of whooping cranes, but they had a serious problem to overcome. Whooping cranes need to migrate. They live up north in summer, then fly south to spend winter in warmer locations. Usually young cranes follow older cranes when they migrate. How would the scientists...