These semi-buried, hole-ridden-surfaced, strangely shaped rocks, surrounded by the tree-like sand patterns, look other-worldly and nearly animate to me.  Skeleton?  Shell?  Artifact?  Nope, just a sea-created rock.  The holes may  be due to secretions by sea creatures.  But doesn’t this look like it could be on another planet?  I’m so glad I’m able to walk on the beach again, free of biting insects!