I found this in northern wisconsin while digging

[BrianG]

Please help identify. I have been trying to find any information on this fossil I found while digging here. its been a long search. I have been told a few thing but have been told here is the place to get things identified. I have only cleaned a few sections because Im afraid of breaking it. it is semi fragile and other sections are very hard.

[connorp]

Some type of coral. @TqB

[Rockwood]

To start with, it looks like a colonial form of rugose coral. 

[Fossildude19]

Something like Acrocyathus.

[TqB]

14 hours ago, Fossildude19 said:

Something like Acrocyathus.

That was my first impression but is there any Carboniferous around there?

EDIT: Apparently not, so it has to be Devonian or earlier. It's hard to go further without knowing the age.

Edited December 29, 2023 by TqB

[Fossildude19]

5 hours ago, TqB said:

That was my first impression but is there any Carboniferous around there?

EDIT: Apparently not, so it has to be Devonian or earlier. It's hard to go further without knowing the age.

 

Maybe something like Hexagonaria, then.

Or Eridophyllum.

[Baking Geologist]

What part of northern Wisconsin? General area is fine.  

[DPS Ammonite]

3 hours ago, Fossildude19 said:

 

Maybe something like Hexagonaria, then.

I believe that all Hexagonaria have corallites that are adjacent to each other with little or no space between them. Plus, the OP’s coral has rounded corallites and not he polygonal ones of Hexagonaria.

 

https://en.m.wikipedia.org/wiki/Hexagonaria

[TqB]

4 hours ago, Fossildude19 said:

 

Maybe something like Hexagonaria, then.

Or Eridophyllum.

Eridophyllum is a possibility.

[FossilNerd]

Acrocyathus was my first thought as well, but as Tarquin said, that may be ruled out because of age. 
 

A very fine example of a colonial rugose coral none the less.