Ammonite Fragment?

[Fullux]

Howdy all,

 

Here's a fragment of aragonite I found in the Coon Creek Formation of McNairy, Tennessee.

 

I would include the previous topic I made on some other fragments I found in the same location in this one, but I'm not exactly sure how.

 

The piece in question reminds me of Baculites, but it could also be Eutrephoceras or sphenodiscus, according to previous research and what I have been told by other members.

 

Does anyone have a guess as to what this could be? It has faint ribbing, and seems to be two fragments sandwiched together.

 

Edited November 24, 2024 by Fullux

[doushantuo]

maybe a bivalve prism like those of an inoceramid?

Edited November 24, 2024 by doushantuo

[Fullux]

47 minutes ago, doushantuo said:

maybe a bivalve prism like those of an inoceramid?

This is the particular material I'm talking about:

 

I have a few other pieces from the same site that look similar. Just trying to see if this particular piece can be ID'd to a specific cephalopod.

[doushantuo]

OK, NOW i see a suture line

[Fullux]

Some other pieces in my collection:

[Coco]

Are these not the same fragments we have seen here ?

Coco

[Ludwigia]

2 hours ago, Fullux said:

 

I have a few other pieces from the same site that look similar. Just trying to see if this particular piece can be ID'd to a specific cephalopod.

 

No it can't in my opinion, since I can't see enough distinguishing features on it which could point to a specific species or even genus. One can just assume that it derives from one of the above mentioned ones, since they all occur in the area and all also can have shell preservation. By the way, please don't overload us with double posts.

[Fullux]

5 hours ago, Coco said:

Are these not the same fragments we have seen here ?

Coco

Yes they are. I mentioned that topic at the start of this one. I would have included it, but was unsure how to. I made this topic specifically for the piece mentioned in my first post on this topic.

[Fullux]

5 hours ago, Ludwigia said:

 

No it can't in my opinion, since I can't see enough distinguishing features on it which could point to a specific species or even genus. One can just assume that it derives from one of the above mentioned ones, since they all occur in the area and all also can have shell preservation. By the way, please don't overload us with double posts.

My deepest apologies, I had thought the other post was inactive.

 

Should I label this piece as Cephalopoda indet.?

[doushantuo]

Posting this because there is a slight change it may help 

Bruce Wade on the Ripley 

Don't apologize so deeply. 

 

size 29,6 mB

comprehensive( as such things go)plus 55 plates of ( mostly invertebrate) fossils

 

The_Fauna_of_the_Ripley_Formation_on_Coo.pdf

Edited November 24, 2024 by doushantuo

[doushantuo]

Microfossils and biostratigraphy of the Upper Cretaceous Coon Creek Formation Lagerstätte, Mississippi Embayment, USA
Authors: Jean M. Self-Trail https://orcid.org/0000-0002-3018-4985 E-MAIL ADDRESS REDACTED, Kristina F. Gardner E-MAIL ADDRESS REDACTED, Jennifer O'Keefe E-MAIL ADDRESS REDACTED, Patricia H. Mason E-MAIL ADDRESS REDACTED, Mark Puckett E-MAIL ADDRESS REDACTED, Michael A. Gibson E-MAIL ADDRESS REDACTED, and M. Maeve McCarty 

I wish i could say it IS the PDF,but it is just the webpage and the document is currently paywalled

 

Microfossils and biostratigraphy of the Upper Cretaceous Coon Creek Formation Lagerstätte, Mississippi Embayment, USA _ Geological Society, London, Special Publications.pdf

Edited November 24, 2024 by doushantuo

[doushantuo]

a nostoceratid found in the Ripley of Alabama

notice the uncoiled part

BTW : obviously NOT an id

[Fullux]

1 minute ago, doushantuo said:

a nostoceratid found in the Ripley of Alabama

notice the uncoiled part

BTW : obviously NOT an id

Are those sutures? Strange how similar they look to those of ammonites.

[doushantuo]

even stranger than that: it IS a (heteromorph) ammonite

Edited November 24, 2024 by doushantuo

[Fullux]

8 minutes ago, doushantuo said:

even stranger than that: it IS a (heteromorph) ammonite

Ah, yes, my bad. I was thinking it was a gastropod of some sort.

[Ludwigia]

2 hours ago, Fullux said:

Should I label this piece as Cephalopoda indet.?

Probably your best bet, but you could also include your guesses in brackets

[Fullux]

@Ludwigia

 

I was looking at the baculites specimen I had included (not mine) and the nacreous shell material on its surface appears to have two layers like my piece. Your thoughts? 🤔

 

[Ludwigia]

31 minutes ago, Fullux said:

Your thoughts?

 

This is normal. All mollusc shells have several layers.

[Fullux]

4 minutes ago, Ludwigia said:

 

This is normal. All mollusc shells have several layers.

Would you still say this is cephalopoda indet., rather than some other sort of mollusk?

Edited November 24, 2024 by Fullux

[Ludwigia]

9 hours ago, Fullux said:

Would you still say this is cephalopoda indet., rather than some other sort of mollusk?

From all of the indications you have given, I would say probably yes.