Help Identify These Fossils Rocks - Lake Michigan

[bluebit25]

I collected some weird fossil rocks today from Lake Michigan in Wisconsin, what are they?

 

 

[bluebit25]

[Tidgy's Dad]

The first featured one is a polished piece of coral and I think that last one is cross sections through lots of bits of crinoid stem. 

The one in the middle could be showing the chambers of a nautiloid. 

[Pippa]

Welcome to the forum bluebit! Just like you, I collect fossils and geo rocks on Lake Michigan beaches of southern WI as well as my hometown beaches in northern Illinois. 

 

I believe the fossil in your first photo might be an aphroid colonial rugose coral. I believe I can see the shape of a corallite in your  photo.  A focused picture of the top would help us see any details if they are preserved.

 

 

A couple of weeks ago, I found something that looks just like that fossil. I started an ID help thread and super knowledgeable and always helpful @TqB suggested to google "aphroid coral", as it might be something like  Arachnophyllum or similar (Silurian). 

 

Here is that thread for comparison: 

 

[TqB]

The first is certainly a chunk of bubbly dissepiments from a rugose coral - it could well be a fragment of an aphroid one as @Pippa suggests (thanks for the kind comments!) but there may not be enough of it to be sure.

 

The second looks like fragments of rugose coral with shelly bits. The chambered bit seems to be a tangential section through some rugose septa i.e. the outside edge of a solitary horn coral) and the toothed bit at the top of its last photo shows the same thing in transverse section.

 

The last one looks like a syringoporid tabulate coral, probably Syringopora itself. You can see infundibuliform (funnel shaped) tabulae and connecting tubes. 

 

 

[FossilNerd]

8 hours ago, Pippa said:

I started an ID help thread and super knowledgeable and always helpful @TqB

I agree! @TqB is always very helpful and knowledgeable. Especially about all things coral. I have learned more than a few things from him. I also agree with his assessment of what you have.  
 

@bluebit25
I love you first specimen with the dissepiments visible. 
 

I’m always torn between polishing fossils or not polishing them. Some polished specimens can be very beautiful and display well, but you may polish away important details, and make the specimen unrecognizable, to get to the beautiful part.

However, when nature makes the decision for you, it’s easy to appreciate the exposed beauty of the polished.

[bluebit25]

9 hours ago, Pippa said:

Welcome to the forum bluebit! Just like you, I collect fossils and geo rocks on Lake Michigan beaches of southern WI as well as my hometown beaches in northern Illinois. 

 

I believe the fossil in your first photo might be an aphroid colonial rugose coral. I believe I can see the shape of a corallite in your  photo.  A focused picture of the top would help us see any details if they are preserved.

 

 

A couple of weeks ago, I found something that looks just like that fossil. I started an ID help thread and super knowledgeable and always helpful @TqB suggested to google "aphroid coral", as it might be something like  Arachnophyllum or similar (Silurian). 

 

Here is that thread for comparison: 

 

 

I made some more pics and a video, I hope it will help. Since it's crystallized I can shine light thru it

[bluebit25]

More pics

Edited March 23, 2020 by bluebit25

[bluebit25]

I made two videos, but my video skills aren't the best.

 

 

 

Edited March 23, 2020 by bluebit25