Complex sentence: Many Maritime Archaic people were buried with great auk bones, and one was buried covered in over 200 auk beaks, which are assumed to have been part of a cloak made of their skins.
Split into simpler sentences: Many Maritime Archaic people were buried with great auk bones. One was buried covered by more than 200 auk beaks, which are presumed to be the remnants of a cloak made of their skins.