Lobster-lip critter.

Scientists in Denmark have discovered a wacky new species unlike any other living thing. Its surprising habitat: the lip of a lobster.

Like lobsters--and humans--the tiny critter belongs to the animal kingdom, the broadest group in which scientists classify (categorize) living things. But the new species didn't fit in with any of the other subgroups, or phyla, of animals, like Chordata (animals with backbones), Arthropoda (spiders, insects, and crustaceans), and Porifera (sponges).

The most unique characteristic of the new critter is that it reproduces in two ways (instead of one). Sometimes it mates with other individuals of its kind to produce offspring. But more often it forms buds, outgrowths that break off and develop into new critters.

The animal also has odd eating habits, scientists say. It uses little "hairs" called cilia to sweep the lobster's leftover food into its own mouth, cleaning the lobster's lips in the process.

These unique traits led scientists to create a new phylum for the species. It's called Cycliophora--Greek for "carrying a small wheel"--because of the animal's round, hairy mouth. And since the creature lives with the lobster in symbiosis--a harmonious relationship in which both benefit--scientists named the new species Symbion pandora.

Symbion pandora probably has many undiscovered relatives, says Simon Conway Morris, a paleontologist at the University of Cambridge in England. To find these species, scientists will study other shellfish to see if they, like the lobster, have tiny animals stuck to their mouths.