Coral or plant. West central illinois

[OHD]

Awesome fossil of something just not sure what. If any bmf can help me . Much appreciated 

[doushantuo]

I think it's the bryozoan Archimedes

[izak_]

i agree with doushantuo 

really nice specimen 

[Rockwood]

Yes. The coiled axis. The fenestra would have extended in a spiral from it.

[doushantuo]

mcGmcKtmaoc-2.0.co%3B2.pdf

[doushantuo]

I'm afraid the paleobiologically interesting McKinney piece in Historical Biology is (still)paywalled. 

It might have been the first paper proposing the mode of reproduction(asexually,by colony fragmentation)