The "remarkable," yard-long, horseshoe crab-like arthropods roamed in swarms of up to a thousand animals, a new study suggests.

From embryonic wasps that mature inside "brainwashed" caterpillars to developing sharks with "superhuman" senses, see pre-birth pictures of animals that have extreme adaptations to the rigors of gestation.

At a Brazilian wild cat conservation center, experts go to extremes to keep rare cats from going tame—from hiding food to smearing chicken blood. Video.

The big fish of the Caribbean reefs are disappearing due to unchecked overfishing, though programs to work with small-scale fishers are underway, experts say.

A four-legged quake survivor gets help, police find an ancient Hebrew document, Bolivia's Indians engage in ritual fistfights, and more in this week's selection of the best news photos.

Meet the animal world's "worst" mothers—and find out why their tough parenting may not be so awful after all.

See boxer crabs, "flying" squid, a fish with a mouthful of babies, and other stars of a marine science school's annual amateur underwater-photo contest.

For decades, scientists have been unable to explain the annual disappearance of the world's second biggest shark. Now, answer in hand, experts are "really blown away."

Given away by bird poop on his socks, a man was charged Tuesday in California with smuggling exotic Asian songbirds from Vietnam into the United States.

Toxic gases have been continually erupting from the fast-growing Pacific volcano since 2004, a new expedition reveals. But some odd new animals seem to like it just fine.

The European Parliament has voted to ban the import of seal products, mainly from Canada, in an effort to stop that country's annual seal hunt—angering some Canadian fishers and Inuit people. Warning: graphic video.

As if global warming isn't giving us enough to worry about, now scientists say it could lead to bigger—and possibly more—spiders of at least one hairy species.

The surprise find doubles the number of frogs and other amphibians in the island country, and suggests "the century of discoveries has only just begun," scientists say.

Two tiny new species of frogs, including the "extremely shy" tiny toadlet, have been discovered in a species-rich region of Australia.

In India's Sundarbans region, tiger-human conflicts are on the rise as tiger habitat and prey disappear and as rising seas push humans into tiger territory. Video.