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Lucid_Bot

Found this the other day in what I think is brush creek limestone. The area is Glenshaw Formation, Carboniferous (Pennsylvanian). All help is appreciated.

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val horn

I have no idea what you have.  I have on occasion found it helpful fill impressions  with dental impression material to see if the positive was more identifiable .  I could imagine yours being from the decorations on a shell, or even an ammonite  

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Crusty_Crab

My first thought is that those are the impressions of the exterior ornamentation of an ammonite. I could be wrong though. Some of the ammonite experts (e.g. @Ludwigia, I apologize if there are others I'm forgetting) may have a better opinion though there is precious little else preserved for a more detailed ID. 

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Ludwigia

I'm not all that familiar with carboniferous goniatites (there aren't any ammonites in this stage. They came along at a later stage), but I don't think that any of them had such obvious spines or nodes.

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Al Dente

There are several nautiloids including Metacoceras that are found in the Brush Creek.

 

 

554870CF-8A2C-4143-9DC8-DA69EAEBB499.jpeg

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Lucid_Bot
3 hours ago, Al Dente said:

There are several nautiloids including Metacoceras that are found in the Brush Creek.

 

Wow, that might be it! Thank you!

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Lucid_Bot

I don't know if this interests anyone, but I went back to the site that I found this specimen and got this from the rock next to it...five nobs in an arch. 

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val horn

good job.  It certainly looks like the positive to your earlier negative, and it looks like an ammonite to me.  Others may be able to id the specific one.

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5 hours ago, val horn said:

it looks like an ammonite to me. 

As previously mentioned, the strata is much too early for ammonites.  

 

Eric's post offers excellent leads.

On 6/27/2022 at 2:33 PM, Al Dente said:

There are several nautiloids including Metacoceras that are found in the Brush Creek.

 

 

554870CF-8A2C-4143-9DC8-DA69EAEBB499.jpeg

 

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Fossildude19

Nautiloid looking like the best bet at the moment.  :) 

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val horn

I thought  amminoids were present from the devonian.  Your insistance that they be referred to as nautaloids  confuses me.  Below is  a description from geokansas.edu

 

 

Ammonoids were squidlike creatures that lived inside an external shell. In fact, ammonoids are relatives of the modern squid, as well as the octopus and chambered Nautilus, all of which belong to the class of animals called cephalopods.

Ammonoid from Pennsylvanian rocks Two ammonoids from Pennsylvanian rocks in southeastern Kansas. The top specimen (from the Eudora Shale Member, Montgomery County) belongs to the genus Goniatites, and the lower specimen (from the Drum Limestone, near Independence) is Schistoceras missouriense.

Ammonoids appeared in the fossil record during the early part of the Devonian Period, about 419 million years ago. They died out about 66 million years ago, during the mass extinction at the end of the Cretaceous.

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westcoast
28 minutes ago, val horn said:

I thought  amminoids were present from the devonian.  Your insistance that they be referred to as nautaloids  confuses me.  Below is  a description from geokansas.edu

 

 

Ammonoids were squidlike creatures that lived inside an external shell. In fact, ammonoids are relatives of the modern squid, as well as the octopus and chambered Nautilus, all of which belong to the class of animals called cephalopods.

Ammonoid from Pennsylvanian rocks Two ammonoids from Pennsylvanian rocks in southeastern Kansas. The top specimen (from the Eudora Shale Member, Montgomery County) belongs to the genus Goniatites, and the lower specimen (from the Drum Limestone, near Independence) is Schistoceras missouriense.

Ammonoids appeared in the fossil record during the early part of the Devonian Period, about 419 million years ago. They died out about 66 million years ago, during the mass extinction at the end of the Cretaceous.

Check out the difference between the order ammononitida and usage of 'ammonites'. There is similar popular usage of 'goniatites' (order goniatida) as a general term for all palaeozoic ammonoids. 

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cngodles
Posted (edited)

Yes, this is 100% the shell of a Metacoceras, from the inside out.

 

As for ammonoids, they are quite rare in the Glenshaw Formation. They preferred the continental shelves it seems, and the seas of the Glenshaw were shallow, and formed during allocyclic events, which during the Late Pennsylvanian were global average temperature swings that would melt continental ice and flood the area with sea water as sea level rose.

 

Some locales in the mid-continental US had workers reporting 500-1,000 ammonoids in a single day. In comparison, "of 60,000 Pennsylvanian aged invertebrate fossils in the OSU (Ohio) collections, only 276 are ammonoid cephalopods".

 

Most from the Pennsylvanian are goniatitic, which are undivided lobes. Think simple sutures with peaks and valleys. The more complex ammonitic sutures are further divided within each suture, creating that almost lightning bolt, blotchy appearance. These started to appear in the Permian (after the Carboniferous).

 

Here is an example of an ammonitic suture. These would never be found in the Carboniferous:

 

Osperlioceras bicarinatum

CG-0000-Osperlioceras-bicarinatum-0001-s

 

And below we have an example of what is probably Schistoceras, a specimen I collected from the Glenshaw Formation. Note the goniatitic sutures, simple, almost like waves.

 

CG-0283-Schistoceras-0002-scaled.jpg

 

 

Edited by cngodles
spelling, corrections.
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Lucid_Bot
8 minutes ago, cngodles said:

As for ammonoids, they are quite rare in the Glenshaw Formation.

Funny because I found another one today. I think it's Brush Creek Limestone.

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cngodles

I’ve only found one in the Brush Creek in four years of searching. Five from the Pine Creek, but it’s much more forgiving in terms of exposing shells intact, which is evident with your Metacoceras up there. The Brush Creek is great for not letting go of the textured outer shell and giving way for the inner smooth steinkern.

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Lucid_Bot
15 hours ago, cngodles said:

I’ve only found one in the Brush Creek in four years of searching. Five from the Pine Creek, but it’s much more forgiving in terms of exposing shells intact, which is evident with your Metacoceras up there. The Brush Creek is great for not letting go of the textured outer shell and giving way for the inner smooth steinkern.

Two more found nearby. How do I remove the matrix from the second one?

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Ludwigia
1 hour ago, Lucid_Bot said:

How do I remove the matrix from the second one?

 

If you don't have a pneumatic air scribe, then you're going to have a tough time with just a hammer and chisel and a lot of luck in the hopes that it doesn't break into bits. If it has a good separation layer, then it might just work, but you'll have to attack it bit by bit.

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cngodles

At least with my experience in the Brush Creek, you can’t easily remove it. You can get an air scribe (Compressor plus scribe minimum $400), but you’ll likely only free the steinkern. I’ve been using one for three years and I still don’t have the skill or patience to free the fossil. shell from the matrix. I’ve always been curious about what a highly skilled professional could do with the Brush Creek limestone, because it’s very hard and brittle.

 

I spent an entire day cutting and scribing a Solenochilus from here to submit to the monthly invertebrate fossil of the month contest. (No. 8, link below). I lost nearly all the shell material, leaving only the steinkern.
 


I will say that using the scribe is fun, and would recommend it to anyone who wants to prep fossils. Wear a mask and eye protection, the limestone debris gets everywhere.

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Lucid_Bot
2 minutes ago, cngodles said:

At least with my experience in the Brush Creek, you can’t easily remove it. You can get an air scribe (Compressor plus scribe minimum $400), but you’ll likely only free the steinkern. I’ve been using one for three years and I still don’t have the skill or patience to free the fossil. shell from the matrix. I’ve always been curious about what a highly skilled professional could do with the Brush Creek limestone, because it’s very hard and brittle.

 

I spent an entire day cutting and scribing a Solenochilus from here to submit to the monthly invertebrate fossil of the month contest. (No. 8, link below). I lost nearly all the shell material, leaving only the steinkern.

I'll just leave it as it is then. 

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