Hallucigenia

Hallucigenia is an extinct genus of animal found as fossils in the Middle Cambrian-aged Burgess Shale formation of British Columbia, Canada, represented by the species H. sparsa, and in the Lower Cambrian Maotianshan shale of China, represented by the species H. fortis. The genus name was coined by Simon Conway Morris when he re-examined the various specimens of Charles Walcott's Burgess Shale worm genus Canadia in 1979. Conway Morris found that what Walcott had called one genus in fact included several quite different animals. One of them was so unusual that nothing about it made much sense. Since the species clearly was not a polychaete worm, Conway Morris had to provide a new generic name to replace Canadia. Conway Morris named the species Hallucigenia sparsa because of its "bizarre and dream-like quality" (like a hallucination). Hallucigenia was initially considered by Stephen Jay Gould to be unrelated to any living species, but most palaeontologists now believe that the species was a relative of modern arthropods.