Scientists have been baffled by a bizarre sea creature that resembles a purple sock for nearly 60 years. According to a BBC report, marine biologists from the Scripps Institution of Oceanography at UC San Diego may have finally cracked the case on the strange denizen of the deep.

The animal, known as Xenoturbella, had remained in scientific obscurity for more than six decades before anybody really knew what it was. Researchers have described four new species of the creature, and believe that they now understand where it fits in the evolutionary history of life on Earth.

Head author Greg Rouse, a professor at the Scripps Institution, says that the animal looks like a purple sock that someone tossed onto the floor. The animal was first described in 1949, but scientists had no clue what to make of it. Initial genetic samples suggested the creature was a mollusk, but Professor Rouse explains that the DNA samples were actually taken from Xenoturbella’s food.

Other theories surrounding the purple sock suggested that it was a highly evolved being, having shed its unnecessary appendages and features in exchange for some untold survival trait.

Fortunately, Professor Rouse and his research team have put an end to the speculation once and for all. Using submersible remotely operated vehicles, researchers have been able to capture some amazing footage of the strange creatures on the bottom of the Pacific Ocean.

Genetic analysis of new specimens indicate that Xenoturbella is actually a very primitive animal. Professor Rouse says that it sits close to the very root of the family tree.

Scientists have never observed the animal feeding, but they have good reason to believe it has a taste for mollusks. In addition to the false DNA test decades ago, researchers spotted most of the new specimens hanging around large beds of mollusks.

And even though the stomachs of the Xenoturbella specimens examined were empty, researchers still found mollusk DNA inside their flesh. The animals have a tiny mouth with no teeth, which would make it very difficult to pry open the hard shell of a clam or a scallop.

When one mystery is solved, another is presented. Researchers will continue to study the Xenoturbella genus in an attempt to discover how the thing eats.

A press release from the Scripps Institution of Oceanography at UC San Diego describing the details of the study can be found here.