Black Shale from Illinois

[bluegilldvm]

This was collected at a private recreation club west of Pit 11 from old spoil hills. I have found Listracanthus spines  from this type of black shale. I’m not sure if this is a large spine or something else. 
 

Thanks

[bluegilldvm]

This is a repost from yesterday and I'm hoping to get some responses today.  This was collected in Pit 14 (west of Pit 11) on the surface of old spoil mounds.  I have found listracanthus spines from this area.  Any ideas what this could be?  

 

Thanks

Edited December 8, 2020 by bluegilldvm

[Huntonia]

Patience is important when it comes to IDing fossils. At times it takes days or weeks to get the right pair of eyes on a certain piece, especially something partial like this.

As such we ask you avoid making duplicate posts. A moderator will likely combine your threads soon

 

As far as the actual fossil goes, @connorp may have some insight.

[RCFossils]

It appears to be a partially exposed/preserved arthropod named Concavicaris sinuata.

They are fairly abundant in certain sections of Illinois black shale.

Concavicaris is a Thylacocephalan.

They are very unusual bivalved arthropod with huge eyes and raptorial appendages.

Your specimen appears to preserve the anterior end of the animal including a portion of the optic notch.

Here is a more complete example for comparison.

[connorp]

Yes, probably Concavicaris. Also, I believe the shale from Pit 14 is the Excello Shale. Slightly younger than the Mazon Creek deposits.

[bluegilldvm]

10 hours ago, Huntonia said:

Patience is important when it comes to IDing fossils. At times it takes days or weeks to get the right pair of eyes on a certain piece, especially something partial like this.

As such we ask you avoid making duplicate posts. A moderator will likely combine your threads soon

 

As far as the actual fossil goes, @connorp may have some insight.

Sorry @Huntonia.  My lack of patience got the better of me.  

[bluegilldvm]

9 hours ago, RCFossils said:

It appears to be a partially exposed/preserved arthropod named Concavicaris sinuata.

They are fairly abundant in certain sections of Illinois black shale.

Concavicaris is a Thylacocephalan.

They are very unusual bivalved arthropod with huge eyes and raptorial appendages.

Your specimen appears to preserve the anterior end of the animal including a portion of the optic notch.

Here is a more complete example for comparison.

Thanks @RCFossils -- I appreciate the ID and information on the species.  

[bluegilldvm]

9 hours ago, connorp said:

Yes, probably Concavicaris. Also, I believe the shale from Pit 14 is the Excello Shale. Slightly younger than the Mazon Creek deposits.

Thanks @connorp  -- I appreciate the information.  

[Huntonia]

8 hours ago, bluegilldvm said:

Sorry @Huntonia.  My lack of patience got the better of me.  

No worries, glad you got your answer. That's quite an interesting one