A deep-water creature once thought to be one of the world's largest sea anemones actually belongs to a new order of marine life.

A new DNA-based study led by the American Museum of Natural History has established the first tree of life for sea anemones, a group that includes more than 1,200 species.

The findings, published in the journal PLOS ONE, describe just how significant this discovery is.

"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," lead author Estefanía Rodríguez, an assistant curator in the Museum's Division of Invertebrate Zoology, said in a statement. "

Rodríguez, along with an international team of researchers, compared particular sections of DNA of more than 112 species of anemones collected from oceans around the world.

Sea anemones are stinging polyps that spend most of their time attached to rocks on the sea floor or on coral reefs. Although they vary greatly in size and color, anemones have very few defining structures, making them difficult to classify.

"Anemones are very simple animals," Rodríguez noted. "Because of this, they are grouped together by their lack of characters. So it wasn't a huge surprise when we began to look at their molecular data and found that the traditional classifications of anemones were wrong."

With tentacles reaching more than 6.5 feet long, the Boloceroides daphneae was initially classified as a sea anemone upon its discovery in 2006. But this study showed scientists that it isn't a sea anemone at all. It has been placed in the newly created order - a classification equal to carnivoria in mammals or crocodilia in reptiles - and is now named Relicanthus daphneae.

This animal may look like a sea anemone, but Rodríguez said labeling it as such would be like "classifying worms and snakes together because neither have legs."

It may seem like a small victory, but to Rodríguez, "this amazing finding tells us that we have so much more to learn and discover in the ocean," he said.