Initially, it was believed the simple organism was more like a flatworm, and had evolved from much more complex animals. "When Greg [Rouse, the study's lead author,] first spotted the worms gliding through a clam field in Monterey Bay, we jokingly called them purple socks," said scientist Robert Vrijenhoek, a co-author of the study.
Now, scientists see that "purple socks" are so simple is because they are very, very old, and they haven't had much reason to change during all this time.
"By placing Xenoturbella properly in the tree of life we can better understand early animal evolution," said Rouse.
"I have a feeling this is the beginning of a lot more discoveries of these animals around the world." We hope so.