In 1950, scientists discovered a strange creature living in the depths of the ocean. For the last six decades, scientists have been trying to figure out the origins of the animal, Xenoturbella, which looks a bit like an old purple sock, and has no eyes, gills or brain. Now, researchers believe they’ve figured out where this alien of the deep falls in the hierarchy of the animal kingdom.

According to a recent study published in Nature, the Xenoturbella belongs near the base of the evolutionary tree. In the past, researchers believed it could have evolved from a much more complex animal. As it turns out, the worm-like creatures are "evolutionarily simple" bilaterally symmetrical animals.

Scientists from Scripps Institution of Oceanography have been researching the Xenoturbella for the last twelve years, and managed to collect several specimens whose genomes were then sequenced. They discovered that not only were the specimens genetically related to other bilaterally symmetrical animals (animals with “matching halves through a line down the center” like worms), but contained four new species.

“The findings have implications for how we understand animal evolution,” said Scripps marine biologist Greg Rouse. “By placing Xenoturbella properly in the tree of life we can better understand early animal evolution.”

“I have a feeling this is the beginning of a lot more discoveries of these animals around the world,” Rouse said.

[h/t: CNET]

Banner Image Credit: Scripps Oceanography, YouTube