Bond Formation Chondrichthyan fossil tooth from Oglesby, Illinois

[Joseph Fossil]

During my trip to a Bond Formation Rock formation in Oglesby, Illinois on October 8th, 2022, one of the limestone blocks I found had a small reddish fossil sticking out on the side of the rock. It was about 2mm in length so pretty small. I thought it was interesting  so I brought it back with the rest of the fossils collected that day. There was not a lot of room in my garage for the block so I put it outside on a supply bin for a while. The next couple of days, It rained ALOT. One day I remembered that the calcite in limestone dissolves in rain, so I went out that night to check on what could be revealed.

 

I was pleasantly surprised at what I found!  The rain had exposed more of the fossil to the surface. I believe it's a Chondrichthyan tooth or a piece of a brachiopod, but I'm not 100% sure so I was wondering anyone could give a proper ID for the specimen?

 

 

 

[Joseph Fossil]

Here are some better close ups of the specimens (sorry for the blurry photos, I'm going to fix my camera soon)!!!

 

 

 

 

[Fossildude19]

Granted, the pictures are pretty blurry, but I am not seeing any texture to points this out as a chondrichthyan tooth to me. 

[Tidgy's Dad]

Looks more like a little rugose coral. 

[Joseph Fossil]

@Fossildude19 @Tidgy's Dad Thanks for the ID! It does look little like coral and I've never seen chondrichyan teeth from that formation that reddish color! I think a coral ID is correct! I'm going to repair my camera soon and get this thing under a dissecting scope and microscope. 

[Joseph Fossil]

Here are better photos of the specimen under a dissecting scope (I was able to get it off the limestone block in a few pieces but it's still pretty intact)!!!

 

 

 

 

 

 

 

[Fossildude19]

Pictures of the bottom edge might be helpful.

[deutscheben]

This one does look potentially like a partial tooth to me- as @Fossildude19 said, clearer images of the edge could confirm if it has the typical internal structure for teeth.

[Joseph Fossil]

@Fossildude19 @deutscheben Good point! Here are some clearer photos!!

 

(1)

 

(2)

 

(3)

 

(4)

 

(5)

 

(6)

 

(7)

 

[Fossildude19]

This looks more like a fish scale to me.

 

@jdp

[deutscheben]

That is definitely vertebrate material, but what part I am not certain. 

[jdp]

Definitely vertebrate. Might be the base of a chondrichthyan tooth or denticle, though part of me is thinking this might be lungfish. Is this a marine or freshwater horizon? Do you know?

[Joseph Fossil]

16 hours ago, jdp said:

Definitely vertebrate. Might be the base of a chondrichthyan tooth or denticle, though part of me is thinking this might be lungfish. Is this a marine or freshwater horizon? Do you know?

 

@jdp It's from Bond Formation marine deposits. 

 

[Joseph Fossil]

On 12/12/2022 at 1:16 PM, Fossildude19 said:

This looks more like a fish scale to me.

 

@jdp

 

@Fossildude19 @deutscheben @jdp To me, it kinda looks like a Deltodus tooth. Besides Chondrichthyans, what other fish species are present in the Bond Formation (Pennsylvanian, Carboniferous) of Oglesby, Illinois?

 

 

[Fossildude19]

Sorry. Not familiar with that area. 

[RCFossils]

Megalichthys scales are fairly abundant in the Bond.

My guess is that it might be a portion of a meg scale.

[jdp]

Texture is wrong for megalichthyid. In a megalichthyid, it would be enameloid.