The gremlin-like pygmy tarsier, discovered during an expedition this summer, had not been seen alive since the 1920s.

The first evidence of a nest from a carnivorous dinosaur related to birds has been discovered by a Canadian paleontology team.

A Jurassic "party" left more than a thousand footprints and rare tail-drag marks at an ancient oasis in Arizona, a new study says. But some experts doubt the marks were left by dinosaurs.

Lonesome George is the last of a Galápagos tortoise subspecies. After 36 years the aging tortoise finally fertilized eggs of a female tortoise, but most are unlikely to hatch.

Cuba is the only country that meets the criteria for sustainable development from the conservation group WWF. But concern persists for once thriving Caribbean marine turtles.

Thousands of wild mustangs kept in U.S. government holding pens may have to be euthanized unless alternatives are found, according to a new federal report released this week.

The Supreme Court ruled Wednesday that military training trumps protecting whales in a dispute over the Navy's use of sonar in submarine-hunting exercises off California.

A Peruvian association is offering U.S. President-elect Obama's family Machu Picchu, a hairless, hypoallergenic puppy. Obama's daughter Malia is allergic to most breeds.

A bizarre-looking bird's social behavior affects seed dispersal and ecological health.

When male fiddler crabs lose their single, gigantic claw, the crustaceans regrow a flimsy replacement that looks just as strong as the first.

From cannibalistic trout to 14-foot stingrays—a series on gargantuan freshwater fishes has won the 2008 American Association for the Advancement of Science award for online science journalism.

Blind lobsters, impossible jellyfish, and ancient bacteria are among the latest discoveries from the Census of Marine Life ocean survey.

Researchers have filmed dophins' behaviors, which include flipper rubbing, to better understand the behaviors' meanings.

The evolutionary ancestor of many of the world's deep-sea octopus species is still living, according to a new gene study of new species and other animals.

Hair has only ever been known to grow on mammals—but it's rooted in the claws of an ancient reptile, a new study says.