Is this a coprolite?

[Vopros]

I bought this rock online auction site.

it was sold as a Permian Coprolite with bones from Oklahoma.

it is 2 cm long.

The last 5 images are microscopic.

what do you think?

 

Edited April 28, 2023 by Vopros

[Fossildude19]

Looks like a coprolite to me. @Carl  @GeschWhat

[Vopros]

On 4/28/2023 at 8:03 AM, Fossildude19 said:

Looks like a coprolite to me. @Carl  @GeschWhat

Thank you, Tim!

I wonder what is this thing? It looks as skin, is it not?

Edited April 29, 2023 by Vopros

[Fossildude19]

Looks more like bone or cartilage.

[Vopros]

53 minutes ago, Fossildude19 said:

Looks more like bone or cartilage.

Thank you, Tim!

could you, please, tell me if all animals have cartilage,

and how one could tell apart fossil skin and fossil cartilage.

IMO they look kind-of similar

 

[Vopros]

Also the thing in question is marked with the red arrow. What are the things marked with the blue arrows? Are they bones?

[Fossildude19]

I'm sorry, but I have very little knowledge of fossilized skin.

But there were xenacanthid sharks where this was found, which to me, would indicate cartilage over skin.

Like I said, it could also be bone, like some kind of ornamented fish bone. 

[Vopros]

2 hours ago, Fossildude19 said:

I'm sorry, but I have very little knowledge of fossilized skin.

But there were xenacanthid sharks where this was found, which to me, would indicate cartilage over skin.

Like I said, it could also be bone, like some kind of ornamented fish bone. 

Here is a closeup. In the upper portion of the image there are thin lines in between the features. Maybe this will help you to ID what it is?

 

[Carl]

On 4/28/2023 at 11:03 AM, Fossildude19 said:

Looks like a coprolite to me. @Carl  @GeschWhat

Sure looks legit to me. And I completely agree with chondrichthyan cartilage. Lots of that come from these beds and the taphonomy is not the type from which one would expect fossil skin.

[Fossildude19]

Thanks for chiming in, @Carl !

 

BTW, @Vopros,   Carl is the go to guy for coprolites.

[Carl]

12 hours ago, Fossildude19 said:

Thanks for chiming in, @Carl !

 

BTW, @Vopros,   Carl is the go to guy for coprolites.

And @GeschWhat, too. She really knows her stuff!

[Vopros]

54 minutes ago, Carl said:

Sure looks legit to me. And I completely agree with chondrichthyan cartilage. Lots of that come from these beds and the taphonomy is not the type from which one would expect fossil skin.

Thank you, Carl! I wonder if this “chondrichthyan cartilage” could be actually coral? See the separation lanes? 

 

[Fossildude19]

I wouldn't expect to find coral in a coprolite, but I would expect to find shark cartilage. 

Cartilage does look like this with the separation lines.

[hadrosauridae]

2 hours ago, Vopros said:

Thank you, Carl! I wonder if this “chondrichthyan cartilage” could be actually coral? See the separation lanes? 

 

 

This is 100% cartilage, which is most likely shark cartilage from a xenacanthid.  So this is a coprolite from a predator that ate a shark (among other things), but this doesnt look like a shark coprolite, even though they were known to be cannibalistic.   That greatly narrows the range of critters it could be from.

Edited May 1, 2023 by hadrosauridae
additional info

[Vopros]

46 minutes ago, hadrosauridae said:

 

This is 100% cartilage, which is most likely shark cartilage from a xenacanthid.  So this is a coprolite from a predator that ate a shark (among other things), but this doesnt look like a shark coprolite, even though they were known to be cannibalistic.   That greatly narrows the range of critters it could be from.

Thank you! If this is shark’s cartilage, then is there a shark’s tooth on the attached image?

One more question.. This Coprolite is very small (2 cm. In length).
Is not this too small for an animal that fed on a shark?

BTW at least in the modern time I did see some animals feeding on sharks.

For example, here is a sea lion consuming a leopard shark.

As you see there are seagulls trying to catch a piece.
So I wonder, if his is possible that a bigger animal actually killed a shark

and a smaller one (the one that left a Coprolite) was just feeding on the pieces?

Also, this Coprolite is from Oklahoma. Were there sharks in Oklahoma?

Thank you!

[hadrosauridae]

Your pic doesnt look like a xenacanthid tooth (and yes, they were a very common freshwater shark in Oklahoma).  Xenacanthid teeth are tri-cuspid.    

 

This is a permian shark tooth

 

[Vopros]

 Thank you!

If it is not a tooth, then what it is? It does not look as a bone either IMO.

And there are more inclusions similar to this one. Some of them appear to have rims.
 

Edited May 1, 2023 by Vopros

[Carl]

22 hours ago, Vopros said:

Thank you, Carl! I wonder if this “chondrichthyan cartilage” could be actually coral? See the separation lanes? 

 

Still only seeing cartilage. Plus, those deposits are all fresh water. And finally, I've never heard of any invertebrate fossils being preserved in those beds.

[Carl]

Scavenging could easily get a small piece of cartilage from a large shark into a small predator.

[Vopros]

1 hour ago, Carl said:

Still only seeing cartilage. Plus, those deposits are all fresh water. And finally, I've never heard of any invertebrate fossils being preserved in those beds.

I was able to contact the seller at last, and he told me about the attached image

”Looks like it could be shark cartilage and a tooth below it. It’s from an Orthocanthus fresh water shark.”

You too believe it is a shark tooth below the cartilage?

Thank you!

[Carl]

2 hours ago, Vopros said:

I was able to contact the seller at last, and he told me about the attached image

”Looks like it could be shark cartilage and a tooth below it. It’s from an Orthocanthus fresh water shark.”

You too believe it is a shark tooth below the cartilage?

Thank you!

That doesn't look like an Orthacanthus tooth to me. Could be a fish scale or a bone fragment but it's really hard to be sure here.

[GeschWhat]

The lighter area by the red arrow looks like coprolite, but most of this looks more like some sort of bone bed matrix to me. 

I think this might be an Orthacanthus denticle (from mucous membrane). I agree with the others regarding the cartilage. This might be a denticle as well.

Edited May 7, 2023 by GeschWhat