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/ Source: Live Science

Lurking in the deep sea is a marine creature thought to be one of the world's largest sea anemones. But new research suggests that the monster, which has tentacles measuring more than 6 feet (2 meters) long, isn't an anemone but rather the first known organism in a new order of animals.

In the four-year study, researchers created a "tree of life" for sea anemones, which are sometimes called "flowers of the sea" but are actually stationary meat-eating animals.

In doing so, they examined the DNA of Boloceroides daphneae — discovered in 2006 in the deep Pacific Ocean — and found the creature stood out as not fitting on the sea anemone tree of life at all.

Image: Anemone-like animal
The newly named Relicanthidae sea creature, which lives near hydrothermal vents, was previously thought to be a giant sea anemone (order Actiniaria). New research places this animal in a new order — a classification equal to Carnivora in mammals or Crocodilia in reptiles.NERC CHESSO Project

Researchers have now renamed the species Relicanthus daphneae, placing it into a new order (the equivalent of Carnivoria for mammals, Crocodilia for reptiles or Actiniaria for sea anemones) within the subclass Hexacorallia, which also includes anemones, black corals and stony corals.

"The discovery of this new order of Cnidaria — a phylum that includes jellyfish, corals, sea anemones and their relatives — is the equivalent to finding the first member of a group like primates or rodents," Estefanía Rodríguez, an assistant curator in the American Museum of Natural History, said in a statement. [See Images of the New Creature and Wacky Sea Anemone]

So why does the oddball look like a sea anemone?

Its similarity to anemones is an example of convergent evolution, which means that two different branches of the tree of life form features that look the same, the researchers said. "Both groups of animals lack the same characters, but our research shows that while the anemones lost those characters over millions of years of evolution, R. daphneae never had them," Rodriguez said.

The findings were published online May 7 in the journal PLOS ONE.

— Elizabeth Howell, LiveScience

This is a condensed version of a report from LiveScience. Read the full report. Follow Elizabeth Howell on Twitter. Follow Live Science on Twitter, Facebook and Google+.