DISCOVER MAGAZINE - It’s the beginning of the spooky season, which means ghouls, ghosts, and bloodsuckers abound. One of the most famous bloodsuckers in nature is, of course, the leech. These parasites feed on blood and have been used throughout history to treat a whole host of medical problems in humans.
Now, for the first time, researchers have found a complete fossil of an ancient leech. Published in PeerJ, the study of this rare fossil has pushed back the presence of leeches on Earth to about 480 million years ago. The fossil also revealed something shocking: ancient leeches did not feed on blood. Instead, they likely swallowed soft-bodied organisms whole or feasted on their internal fluids.
“We don’t know nearly as much as we think we do,” said Karma Nanglu, a paleontologist at the University of California - Riverside, in a press release. “This paper is a reminder that the tree of life has deep roots, and we’re just beginning to map them. It’s a beautiful specimen. And it’s telling us something we didn’t expect.”