After four decades of confusion, scientists have finally figured out how to classify a creature so surreal it was given the name Hallucigenia. The tiny creature, found in fossils from the "Cambrian Explosion" of diverse life 500 million years ago, has 14 to 16 legs and large spikes on its back, and researchers have long puzzled over which end of it is meant to be in front. But after taking a close look at its claws, scientists have concluded that it isn't an evolutionary one-off as was once thought, but a relative of the tiny "velvet worms" with stubby legs that can still be found in tropical forests today, the Independent reports.
Researchers say that the claws have much in common with the jaws of the velvet worms, which "are no more than legs modified for chewing," the Washington Post reports. The connection is exciting, researchers say, because it upends the previous understanding of the family tree of insects and other arthropods. "It's often thought that modern animal groups arose fully formed during the Cambrian Explosion," the lead researcher says in a press release. "But evolution is a gradual process: Today's complex anatomies emerged step by step, one feature at a time. By deciphering 'in-between' fossils like Hallucigenia, we can determine how different animal groups built up their modern body plans." (A crazy recent fossil find: penguins the size of NBA players.)