Until last year Hallucigenia was one of the strangest animals that ever lived. This sausage-shaped sea creature, which died out half a billion years ago, early in the Cambrian Period, was said to have walked on seven pairs of spikes and to have sported a row of wavy tentacles along its back. But last year, in the Yunnan province of China, paleontologists dug up some new specimens closely related to Hallucigenia. Those fossils made clear that the Hallucigenia researchers had known was a figment of their imagination: they had been looking at it upside down.
With the spikes now protecting its back and the tentacles converted into two rows of legs, Hallucigenia has joined the class of onychophoran-like animals, whose modern representatives look a little like centipedes--homely, perhaps, but not exotic at all. Yes, a bit embarrassing, concedes Simon Conway Morris, the British paleontologist who described and named Hallucigenia back ...
