to me I see a shell looking base and maybe a pedicle like a brachiopod but to me it looks like attached to the opposite end of the (maybe) pedicle is a fan shaped sponge looking thing and to my knowledge brachiopods don't have that... what I see is some shelled creature buried in the mud extending out some kind of sponge looking thing to feed I just don't know what kind of animal it is. but I'm no brachiopod expert so could be...
Genius prevails!!!
I thought it was George.
Most likely a brachiopod as previously posted.
That "feeding" tubercle is just a partial of the same type of shell.