Horn Coral Id Help Needed

[jpc]

Hi folks-

I am posting these for a friend. He asked me for help and I know nothing about Paleozoic horn corals, beyond, "Yup, them's horn corals". Can anyone help ID these beyond my skill level.

This is from his email;

Enclosed are photos of the unknown coral from the Madison Limestone. I'm
open to any guesses. Would also appreciate name of someone who might be
familiar with coral of this time period.

[jpc]

And this one too.

Thanks, y'all

[Fossildude19]

I can't really help much here, but, has he looked at THIS PDF?

Might help to narrow down the likely culprits.

A jumping off point, at least.

Regards,

EDIT: also found THIS - available as an e-book for $7.99.

Edited June 11, 2015 by Fossildude19

[abyssunder]

A starting point in the ID could be also Corals From Well Cores of Madison Group, Williston Basin - By WILLIAM J. SANDO http://pubs.usgs.gov/bul/1071f/report.pdf

[Scuter]

Perchance was this found in the bighron mountains?

[Scuter]

 most left sanded off sides and most right internal structure

 

Try doing the old jack horner and cut one open so you can have a look inside. Now you should something like this kind of structure and if you don't it's not a horn coral. Because I am not so convinced it's not a horn coral. 

Edited August 6, 2018 by Scuter