Coon Creek Vertebrate?

[Fullux]

These are a few things that some of my family members found when we went on a hunt in the Coon Creek Formation in McNairy County, Tennessee. I'm pretty sure the smaller one is just some hematite formation but I'm not sure about the other one.

[crinus]

I think that is the bottom valve of a Exogyra.

Joe

 

[Fullux]

58 minutes ago, crinus said:

I think that is the bottom valve of a Exogyra.

Joe

 

They can get that big?

[ClearLake]

3 hours ago, Fullux said:

They can get that big?

There is no scale indicated, so we don't know how big they are.  But Exogyra can get pretty large, at least as large as the palm of your hand (OK, an average hand, I don't know how large your hand actually is- ).

[Fullux]

6 minutes ago, ClearLake said:

There is no scale indicated, so we don't know how big they are.  But Exogyra can get pretty large, at least as large as the palm of your hand (OK, an average hand, I don't know how large your hand actually is- ).

My hand is about 7-8 inches and is about as long as the fossil.

[JohnJ]

Try some photos of the larger piece while damp.  Photos of the broken edges would be useful, too.

[Fullux]

5 hours ago, JohnJ said:

Try some photos of the larger piece while damp.  Photos of the broken edges would be useful, too.

Is it just me or does this look like trabecular bone?

[Fullux]

Dampened as requested.

[Fullux]

[Fullux]

[ClearLake]

The more I look at it, especially the last photo, I see a concretion, not a fossil at all.  I see from a quick internet search that concretions are common in certain parts of he Coon Creek Formation.  Of course it also has very well known fossil assemblages.

[Creek - Don]

On 3/3/2023 at 3:10 PM, Fullux said:

My hand is about 7-8 inches and is about as long as the fossil.

Yes, they can be very big.  Here is the biggest one that I found in the North Sulfur River. 

[Fullux]

I found this specimen in the Coon Creek formation back in 2017 and have been trying to identify it for a while. I've made a post about this particular specimen on here before and it was labeled as iron formation or large exogyra and forgotten about. I'm affraid I'm just not satisfied with that label.

 

This specimen is in two pieces that connect and when observing the inner structure of it I noticed that it has traces of trabecular bone, which for those of you who may not know is the spongy porous material found inside of bones (Pictured below).

 

On the inner face of the specimen, there are many small ridges covering it that are near perfectly spaced. I've included pictures of the specimen when wet and dry to show details.

 

On the day we found this, we were informed that there was a chance for bones of a Prognathodon sp. to be scattered across the area. I'm going to go out on a limb and say that this may be what this specimen is from, though, I am most certainly not an expert, yet.

[Notidanodon]

Hmm tough call but I think it looks more like a weird ironstone concretions, could be wrong though!

[JohnJ]

5 minutes ago, Fullux said:

I've made a post about this particular specimen on here before

 

Please keep the context of previous discussions about the same object in one topic.  Thanks. 

 

 (Topics merged.). 

[FossilDAWG]

The surface of your specimen does not resemble any bone, mosasaur or otherwise, that I have seen from the Coon Creek or equivalent formations.  The object you are holding in your hand, and in the photo with the tape measure, looks like one of the ironstone concretions that are common at some levels, but there is also a resemblance in general profile to a large Pycnodonte mutabilis oyster.  However the first few images also remind me a bit of an Exogyra valve, as has been suggested.  The cross section is ambiguous, I can see the resemblance to trabecular bone, but also to porous ironstone.  All in all I lean towards an ironstone concretion, perhaps one that grew attached to an oyster shell.  I really do not think it is bone.

 

Don