Bronx Zoo cheetahs are attracted to Calvin Klein's "Obsession for Men," which scientists have tested to lure wild big cats close to camera traps.

In a stunning display of amphibian machismo, tree frogs boogie before they brawl in this unprecedented video.

Fossils show that an ancient crocodile had mammal-like teeth and legs.

Scientists this year filmed deep-sea creatures for the first time at depths of more than 4,500 feet near Australia's coast, including the deep-dwelling sixgill shark biting on bait.

Built to rove for 90 days, Spirit has lasted six years on Mars. But now it's stuck and may lose power. Even standing still, though, Spirit can do a surprising amount of science, NASA says.

While battling a blaze on the slopes of Mauna Kea in August, a Hawaii firefighter captured rare footage of a fire tornado, or fire whirl.

An all-black king penguin—a very rare mutant—was spotted and filmed on the sub-Antarctic island of South Grgia.

The vampire squid can turn itself "inside out" to avoid predators—as seen in a video released this year to emphasize the need to protect deep-sea species from the effects of human activities.

An explorer "disappears" into the floor of a pool sacred to the ancient Maya, and divers find the first known fossils in Belize.