1) Burgess Shale animal
Found on
https://www.crosswordclues.com/clue/ancalagon
[genus] Ancalagon minor is an extinct priapulid worm known from the Cambrian Burgess Shale. Because it superficially resembles the modern-day internal parasites known as the acanthocephalids or `spiny-headed worms,` A. minor was once thought to be, or once thought to resemble the hypothetical free-living ancestor of acanthocephalids. {gpb a...
Found on
http://en.wikipedia.org/wiki/Ancalagon_(genus)
No exact match found.
