Odd fossil! Baculite - or something else??

[VRFossils]

This is an odd fossil that was given to me by a friend who has been a fossil and rock collector and seller for years.  It was in a misc. box of fossils.  He said it was baculite, but he didn't have his glasses on, so I'm not sure if he could clearly see it.  The overall shape is right, but I question if it is actually baculite because it doesn't have any of the tell-tale signs on the outside like baculites many times do - shiny surfaces, puzzle-piece looking sections, etc.  I can't really see much of any identifying marks on it at all.

It has a few marks on the outside (and a few in the inside) that look like branching veins or something, but I can't tell what they would be.

 

I really have no idea where this fossil originated from.

 

Any ideas? 

[Tidgy's Dad]

I can see no diagnostic features: shell material; siphuncle, septa or patterning. 

But, yes, the shape is good. 

i'd be doubtful. 

 

[Fossildude19]

I'm not seeing the sutures you would expect with Baculites.  

 

[GeschWhat]

What about a nautiloid siphuncle? We grew them big here in Minnesota. I have found them isolated from other parts of the cephalopod.

[jpc]

Not all baculite fossils have the diagnostic signs.  Many are just the infills of the living chamber, which often have no shell, show no sutures, etc.  Additionally they often have trace fossils on them, which I see in this guy, so my vote is that I see no reason to not call it a baculite.  If only we knew where it came from.