Photos: 'Naked' Ancient Worm Hunted with Spiny Arms

New discoveries

Of Burgess Shale fossil sites, the Yoho National Park site in Canada was the first and is the most famous. A new Burgess Shale fossil bed was found in 2014.

Family tree

This family tree shows how O. cribratus might be related to another extinct, worm-like creature, known as Hallucigenia, as well as water bears, velvet worms and arthropods.[Read the full story on the ancient "naked" worm-like creature]