Crinoid Like Fossils/Rocks Found in Mazon Creek ID

[Tom16]

Hello,

 

While searching for concentrations in Mazon Creek, IL, I discovered you can find Crinoid stems in rocks around the area. I have found a few of those but recently I found a couple that are similar but not as easily identifiable. Below are the two samples in question. Thank you for your time and assistance with the IDing.

 

1) This sample is very similar to the type of rock I find the Crinoid stems in. Seems to be like fossilized coral with the holes. Specifically, I am looking at the spiral with a bump in the center. I think that is an impression of a Crinoid stem that was there before but not sure?

 

2) This sample is a different kind of rock it seems. It is lighter in color and has some sparkles in it. The feature in question is the 'flower bud' type formation I see in the top center of the rock. It is smooth and it has depth. Compared to how the rest of the rock is rough, I have to imagine this is something different. 

 

 

Edited May 1, 2023 by Tom16

[connorp]

These are Silurian glacial erratics.

[Tom16]

2 hours ago, connorp said:

These are Silurian glacial erratics.

Thank you for the ID, much appreciated. Looking now in my fossil book, I see there is a concentration of these fossils around Chicago so that makes sense. Do you have any guesses what the fossils could be showing or are these types of fossils tough to determine?

[FossilNerd]

You are correct about number 1. The round circle with the bump in the middle is an impression of a crinoid columnal. 
 

Number 2 looks like it might be a worn brachiopod to me.