Researchers at the Royal Ontario Museum and the University of Toronto have described an exceptionally well-preserved new fossil species of bristle worm called Kootenayscolex barbarensis. Discovered from the 508-million-year-old Marble Canyon fossil site in the Burgess Shale in Kootenay National Park, British Columbia, the new species helps rewrite our understanding of the origin of the head in annelids, a highly diverse group of animals which includes today’s leeches and earthworms. This research was published today in the journal Current Biology in the article A New Burgess Shale Polychaete and the Origin of the Annelid Head Revisited.