Dinosaurs dying at the end of the Cretaceous Period.

Artist's conception of male Maiacetus inuus with ...

This illustration shows the size of the ...

This fossil fish bridges the evolutionary gap ...

Different genes code for two different forms of ...

Millions of jellyfish gather in a marine lake in ...

This photo was taken by Uwe Kils.

White Shark off the California coast

Humpback whales near the Hawaiian Islands

North Atlantic right whale, an endangered ...

Atlantic bluefin tuna live in open ocean waters

A purple striped jellyfish in the open ocean

Riftia tubeworms, mussels, and scavenging crabs ...

Hydrothermal vent with tubeworms in the ...

These jellyfish were found at hydrothermal vents ...

Perch in giant kelp forest

This fish, the California Sheephead, lives in ...

Pillar coral in the Florida Keys.

Sponges, corals, and gorgonians living in a reef ...

The queen conch (Strombus gigas) is a type of ...

This wolverine looks like a cute little bear.

Corals of Australia's Great Barrier Reef

This pretty postman butterfly was once an ugly caterpillar.

This anaconda is looking for its next prey.

This is an image of ducks -- lifeforms on earth.

The leopard, Panthera pardus, is a member of the ...

Polar Bear