Ghost shrimp burrow or chewed up belemnite or ?

[butchndad]

Good morning

allow me to first say how much I’ve learned from you folks. Admittedly starting from scratch, by reading your posts and then googling words I’m getting a great education. I never knew what concretion or chert or phragmocone meant.  I have a long ways to go but I’m learning 

today’s question is these two photos. They were found in big brook and the longer is one inch long. Chewed up belemnite or ghost shrimp burrow (wouldn’t be porous?) or what?

[Jeffrey P]

Chewed up belemnite pieces.

[Plax]

cliona ridden belemnite frags

[Ludwigia]

Those sponges sure did have a feast on those poor creatures.

[Jeffrey P]

They were already dead and thus probably didn't mind being bored into.