After 50 years, scientists discover head of the insane Hallucigenia 'worm' - The Verge

Sometimes it's hard to tell what an animal looks like when it's been extinct for over 400 million years — just ask Hallucigenia . Scientists have studied the thumb-sized worm for more than 50 years now, and have only just discovered which end is... A new model for the creature includes a ring of teeth around its mouth, a simple pair of eyes, and a foregut lined with tiny little teeth. A weird and wonderful history In 1977, British paleontologist Simon Conway-Morris came across a very weird-looking fossil. And the people who found the 0. 5-inch long fossil had classified it as an annelid worm — worms that include leeches and earthworms. As far as he was concerned, this organism had walked on seven pairs of stilt-like spines, all while waving around the seven wacky tentacles on its back. Conway-Morris’ model was controversial, but it stood until 1991. That year, researchers Lars Ramskold and Hou Xianguang discovered fossils in China belonging to a related animal called Microdictyon — fossils that made Conway-Morris’ mistake quite... Conway-Morris had been looking at Hallucigenia upside-down the whole time. Conway-Morris figured it was the blob-like structure located at one end of the Burgess Shale fossil. Source: