Unusual Pennsylvanian Plant Stem/Cone?

[deutscheben]

Found this while hiking along the Little Vermilion River in East Central Illinois, it was inside a nodule that had split naturally. It didn't match up with anything in the various books on Pennsylvanian plant fossils I have, can anyone identify it? it was on state land, so I left it there, but I'm quite curious about what it is. The exposure at this site is, I believe, the Energy Shale.

[BobWill]

I don't recognize it but have you considered crinoid?

[Fossildude19]

Any idea on the size of the item?

Was this found in Lasalle County?

Looks like the geology there is pretty diverse.

Looks like some Ordovician as well as Pennsylvanian exposures there.

( I don't see any "Energy Shale" listed there. )

Was it dug out of an exposure, ...or lying loose?

So far, I think BobWill may be on the right track.

Regards,

Edited November 24, 2015 by Fossildude19

[deutscheben]

Thanks for responding- to answer your questions: The exposed "bump" was about 1 inch long. This was found in Vermilion County- the Energy Shale is found above the Herrin Coal and is similar to the Francis Creek Shale of Mazon Creek fame, producing sideritic concretions containing primarily plants, but also insects and other terrestrial and freshwater fauna. This nodule was lying loose on the riverbank.

[piranha]

It appears to be a section of Calamites. The characteristic features are more apparent after color inversion and reorienting the image.

[Stocksdale]

I see the Calamites too.

Is the branch partly bent so it almost looks like it goes back into the rock on the left side.

[deutscheben]

Hmm, it seemed more of a club-like "end" to me- I don't think it bent back into the concretion. But it does otherwise resemble Calamites, I can see that now. Could it be the end of a branch segment?

[TqB]

Or a rhizome tip.

Second pic on this page:

http://botanyprofessor.blogspot.co.uk/2012_03_01_archive.html

Edited November 25, 2015 by TqB

[paleoflor]

If anything, the subterranean parts of Calamites bore only root-scars, which are much smaller and do not touch each other laterally (are quite widely spaced, in fact). So, if this would indeed be a Calamites fragment (not convinced yet, though it clearly shows some resemblance), then the ring-shaped structure must represent a whorl of branch-scars. This basically rules out rhizome tip as an option and, as such, the "club-like end" remains a puzzle to me. Any ideas on what the structure around the "Calamites" represents? The rock fractured in a peculiar pattern, if you ask me, almost like it is also a part of the structure, somehow...