Hollowed out Bones, Very Late Pleistocene Beaumont Formation

[darrow]

Among the hundreds of very late Pleistocene age bones and bone fragments I've collected from a local Galveston Bay dredge spoils site, I have four that are hollowed out like the one pictured below.  I believe this to be a proboscidean foot bone.  Anyone recognize this type damage and know of a mechanism that could cause it? 

[darrow]

[caldigger]

My thoughts, it was in the middle of a thoroughfare in an animal's burrow tunnel while buried and the critter chewed right through it to continue the passage instead of going around.

A gopher would easily do something like this.

[fossilnut]

The 2nd and 3rd pictures led me to think this was a large calcareous worm tube colony that formed around something that later was dissolved. But wait for other comments as my eyes are old and I may not be seeing it clearly. Interesting piece. I like ones that beg for a story to be told.

[Harry Pristis]

 

I guess it was shelter for some invertebrate like this example: