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.
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]
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