Fossil Hallucigenia sparsa from the Burgess Shale Courtesy of M. R. Smith / Smithsonian InstituteThe spines along its back were thought to be legs, its legs thought to be tentacles along its back, and its head was mistaken for its tail. The animal, known as Hallucigenia due to its otherworldly appearance, had been considered an ‘evolutionary misfit’ as it was not clear how it related to modern animal groups. Researchers from the University of Cambridge have discovered an important link with modern velvet worms, also known as onychophorans, a relatively small group of worm-like animals that live in tropical...