Adams Co., Il Coprolite - Need Help Narrowing Down Age

[GeschWhat]

Hi all,

I recently acquired this coprolite specimen, and the only information I got from its owner was that it was from Adams Co., IL. The segment is phosphatic and measures 45 mm long with a 30 mm dia. In addition to crinoid inclusions, it looks to have eaten something that looks like coral. Did anything even eat coral? I am not at all familiar with the stratigraphy of the area. Based on what I have read, I am assuming it is carboniferous (Mississippian?), but if anyone out there is familiar enough with the area to narrow that down, it would be greatly appreciated. I am also trying to identify any species in the area large enough to have expelled this beauty that is known to munch on crinoids. Is the crinoid identifiable from the segment shown?

There also appears to be some sort of impression or track on the exterior. Perhaps it can help narrow down the timeline.

Thanks a bunch!

[Auspex]

Huh...

As far as I know, anything that chews on coral pretty much just turns it to sand. I have no idea what would swallow larger bits.

[Plax]

This doesn't look phosphatic to me. While it could be coprolitic; it looks like a rounded piece of fossiliferous limestone or a burrow in-fill.

[Auspex]

+1 for burrow infill. There is a decided lack of candidates for coral/crinoid eaters from the last time that area was a sea.

[Carl]

Hmmm... scratching my head here. Some things about it are definitely coprolitic. But I have the same reservations about it as the others.

[GeschWhat]

It definitely passes the lick test (it sticks to the tongue)...so I'm pretty sure it's phosphatic and not just limestone. It is a weird piece. I was skeptical when I bought it, because of it's size and location. I just don't know enough about the area, and can't think of a critter big enough to have created it. If it did eat crinoids, wouldn't it comprised of calcite rather than calcium phosphate? Maybe part of it washed away and the coral/crinoids are infill? I've noticed that happens with spiral coprolites sometimes. Is that really coral? A while back I posted inclusions from an Eagle Ford Fm coprolite that had what looked like coral, but was thought to be a jaw of an Albulid fish. Link Could it be part of a fish jaw and not coral? Ah, so many questions!

[Auspex]

The lick test might reveal capillary action, but that is not an exclusive indicator of phosphatic content.

I think the 'coral' may be some bryozoan bits; nothing I can see is what I would consider ingestible.