Siphuncle ?

[Rockwood]

From the Pragian Tarratine formation of Maine. I collected it as a trace fossil, but as I was unloading it the light hit it at a shallow angle highlighting the unstained portion of what I think is a nautiloid shell.

[Mark Kmiecik]

The chambers are transversely angled at about 15 degrees. Is that consistent with any known nautiloid?

[Rockwood]

2 hours ago, Mark Kmiecik said:

The chambers are transversely angled at about 15 degrees.

Kind of the way a fish spine falls a little bit askew ?

[abyssunder]

I would go with your initial thought, Dale. I'm not convinced of other than  trace fossil. Maybe ichnos having some kind of backfills? I could be wrong, of course.

[Rockwood]

26 minutes ago, abyssunder said:

I would go with your initial thought, Dale. I'm not convinced of other than  trace fossil. Maybe ichnos having some kind of backfills? I could be wrong, of course.

Planolites are common in the area.