Scientists are baffled by mysterious blood-sucking fish that roamed the sea around 450 million years ago.
The headless fish have three sharp teeth alongside rows of smaller teeth that apparently existed in the Pacific basin.
Their fearsome physical traits allowed them to exist off the blood and other bodily fluids of other aquatic creatures.
Scientists are now trying to work out what role these terrifying-looking creatures played in the world’s oceans.
Known as Pacific lampreys ... Read even more
