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KimTexan

I had the day off yesterday and headed out to the North Sulfur River. Found absolutely nothing of note except lots of wild hog wallows, lots of spiders, the usual petrified wood and a couple Cretaceous bone chips. Had another one of my stupidity inspirered adventures with the heat. It was 100 out there and to make it worse the water was also 100. Made it out in one red bug laden piece.

Recovered, ate lunch and glutton for punishment that I am headed back out at a much easier access point. 

While I was there I found something, which I don’t know what it is. The only thing I can possibly imagine it could be would be a rudist. There are 2 varieties of rudist in the NSR. I believe this is a colony of  Sauvagesia belti rudist, but I’ve never seen one. I believe I was in the Pecan Gap Chalk overlain by the Ozan. The concretion in question I believe to be from the Ozan since it was not in situ, but in a gravel bar.

This is the concretion as I found it. Only 1/3 was exposed. It’s about 8 x 7 inches long and wide and 3.5 at its thickest.

C83ABDBF-B700-47A3-8947-FD973316D5AC.thumb.jpeg.1926aacb73daa39eda29546e6660b18f.jpeg

 

It has an Inoceramus clam on the righ. I have not learned my species, but I think this is the I. balticus. The other species noted there is an I. aff. Barbini. But that is not the key item for ID. There is a hollow chamber in the middle that has shell material inside. I’m working on trying to remove matrix from it so it is a mess right now. This is a top side view.

FC27D494-5872-4C99-9F7C-156EB7239AFC.thumb.jpeg.dac1545b20182c4a95c18870557b7127.jpeg

 

This is a bottom side view.

A36E818A-2017-4BEB-82BD-9970C616A9CA.thumb.jpeg.bd6a2e568836a69e145043f112c7a8d3.jpeg

 

There are the ends of 4 individual organism in view in the pic below. All seem to have been basically tubular and average approximately 4- 5 inches long from what I can tell. In the top of the pic there are 2 perpendicular to each other. One overlaying the other. Bottom of pic are 2 running parallel to each other. I was cleaning the big one on the bottom and came upon the end of another laying on top of it. All 4 have the remnants of nacre on them.

984E395B-9117-4550-9418-1C9530698FB8.thumb.jpeg.a466af755fdcf6aadad29d7881b324ca.jpeg

 

I think there are 5 individuals here. There is a 5th on the bottom of the 2 on the right.

E6F0BDC0-85E9-4145-A970-6A06D3A9FF80.thumb.jpeg.323a384af52598123126bf5f873cb916.jpeg

 

This is one with the full length in view of what is present at least. It is 5 inches long.

4A3800E7-FF04-414B-BB1A-674D84709C43.thumb.jpeg.4480d38bc982eaae74f416e0388ca050.jpeg

 

This is what got me excited after I picked it up and rinsed it off. It is that beautiful dragon skin quality found in nacre. This is on the end of one of the individuals. I believe there are more than 12 in the conglomerate. I’m Still uncovering stuff though.

8D584423-05F1-4C6A-981A-B1C2275C477A.thumb.jpeg.b298e06a902bc48529372f4f70c6a4c4.jpeg

 

Any thoughts as to what they may be would be be greatly appreciated.

 

Thanks, 

Kim

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WhodamanHD

I’ve no clue, but the nacre is beautiful!

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DPS Ammonite

Did you make the cut marks?  

 

In the upper right part of the second photo I see an Innoceramus impression. Could all the pieces with nacre be Innoceramus or possibly another mollusk? I have found several Innoceramus with nacre at NSR, especially in the darker shales.

 

I have never seen or heard of any rudistids preserved with nacre.

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KimTexan

I made the cut marks. I’m still removing matrix. They are absolutely not Inoceramus. They are straight tubes that don’t seem to taper.

The next to last pic is what they all look like. The hollow in the middle is lined with shell material of one of them.

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DPS Ammonite

If they are tubes consider Baculites.

 

Are you able to get close up of fossils ends? Rudistids should have the wood grain texture.

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doushantuo

Antillocaprinids are tubular,but I don't think they are straight.Could be wrong though. 

 

legendaasapheusacoastgplai,ptykanguujjjiidp88humb.jpg

edit,some time later:as posted by (e.g.?)Abyssunder,and kudos to him for doing that

 

http://www.thefossilforum.com/applications/core/interface/file/attachment.php?id=385627

 

legendaasapheusacoastgplai,ptykanguujjjiidp88humb.jpg

 

Last image from the Nair thesis on porosity in Cretaceous carbonates

Rudist are often filled with diagenetically formed  coarsely crystalline equant calcite

 

 

 

 

 

 

 

 

legendaasapheusacoastgplai,ptykanguujjjiidp88humb.jpg

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doushantuo

2f566tyyy4ette44e5tmedtr2mradio35pltwillist.jpg

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JarrodB

I think we have more than 2 varieties of rudists at NSR. I have at least four of five types I've found there that look nothing alike. 

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KimTexan
8 hours ago, JarrodB said:

I think we have more than 2 varieties of rudists at NSR. I have at least four of five types I've found there that look nothing alike. 

Thank you for your input Jarrod! Sincerely thank you. I have been looking for the 2 species of rudists in the river and feeder creeks, but I have only been able to find the Durania and only a few fragments of those.

More than 2 species that’s a bit exciting to hear of. I’m am going off of info from the DPS Occasional Papers volume 4 where they only name 2 varieties of rudist.

Do any you’ve found look like these?

 

Would/could you be willing to share pics of the varieties you have found in the NSR? I have 

 

Sometimes I am sure I see stuff and discount them as nothing and don’t pick them up.  I almost didn’t pick up this concretion, but it has been a very interesting concretion. I also picked up another one twice the size nearby this one that has the same stuff in it with more of the beautiful nacre.

14 hours ago, DPS Ammonite said:

If they are tubes consider Baculites.

 

Are you able to get close up of fossils ends? Rudistids should have the wood grain texture.

I have seen a lot of baculites and they honestly don’t look like any that I have found before. That said the preservation is completely different on these than any baculites I have found at the NSR or otherwise. I can’t tell yet if these taper. I need to get more cleaned off.

One odd thing. One the hollow chamber that is in the center. It appears to be lined with shell fragments, but also the portion of the hollow shaft that is filled seems to have a calcium carbonate, shell plate, that I think either must be a valve. If it were a baculite I would expect to see septa or sutures. I don’t see either of those. 

Here are a couple more pics.

 

 

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KimTexan

Oops forgot the pics.

This is looking down the shaft. Looks like oyster shell at bottom.

6D6B5377-85E5-41D0-BF3B-B499B94E1132.thumb.jpeg.1c099d4165e98c5091315ab0c2b1b977.jpeg

 

More nacre on another one on 2nd concretion.

C66DC103-CDC1-42AD-990C-5888EE4F3B3B.thumb.jpeg.88080c25fade690c63c2566d2ce68303.jpeg

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JarrodB
28 minutes ago, KimTexan said:

Thank you for your input Jarrod! Sincerely thank you. I have been looking for the 2 species of rudists in the river and feeder creeks, but I have only been able to find the Durania and only a few fragments of those.

More than 2 species that’s a bit exciting to hear of. I’m am going off of info from the DPS Occasional Papers volume 4 where they only name 2 varieties of rudist.

Do any you’ve found look like these?

 

Would/could you be willing to share pics of the varieties you have found in the NSR? I have 

 

Sometimes I am sure I see stuff and discount them as nothing and don’t pick them up.  I almost didn’t pick up this concretion, but it has been a very interesting concretion. I also picked up another one twice the size nearby this one that has the same stuff in it with more of the beautiful nacre.

I have seen a lot of baculites and they honestly don’t look like any that I have found before. That said the preservation is completely different on these than any baculites I have found at the NSR or otherwise. I can’t tell yet if these taper. I need to get more cleaned off.

One odd thing. One the hollow chamber that is in the center. It appears to be lined with shell fragments, but also the portion of the hollow shaft that is filled seems to have a calcium carbonate, shell plate, that I think either must be a valve. If it were a baculite I would expect to see septa or sutures. I don’t see either of those. 

Here are a couple more pics.

 

 

I'm  currently offshore so I'm unable to take pics of all of mine but here's an example of a few different kinds I've found. The first 3 in the photo seem very different from the rest. 

gallery_19191_2362_99401.jpg

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JarrodB

I have one more that is even more bizarre than the ones pictured. Mick Tune even said he had never found anything like it. 

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abyssunder

 Rudists don't have nacre preservation, as far as I know. :)
Kim, try to make a transverse cut (polished) on one of the "tubes"( I suggest the lower one from the forth picture.) to see how it looks in transverse section.

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KimTexan
9 hours ago, abyssunder said:

 Rudists don't have nacre preservation, as far as I know. :)
Kim, try to make a transverse cut (polished) on one of the "tubes"( I suggest the lower one from the forth picture.) to see how it looks in transverse section.

These are kind of cross sections of some already exposed. They are layers. I suspect most of them were crushed.

You can’t realky tell from the pics, but it looks like a tube with a thick outer edge that got flattened. The outer edge appears to be layered in thin concentric rings.

Some of the tubes appear to be filled with gray matrix which doesn’t help. No hint of baculite that I can see. Although one variety of baculite I have many fragments of 99% of the time shows no sutures or septa on the breaks.

The shaft with the oyster shell type valve inside indicates to me it isn’t baculite.

E19F4C32-0390-45D6-BDFE-AC636A8C41FE.jpeg

AE82738B-582E-4CE5-BC9E-D912953B2F4A.jpeg

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KimTexan
9 hours ago, JarrodB said:

I'm  currently offshore so I'm unable to take pics of all of mine but here's an example of a few different kinds I've found. The first 3 in the photo seem very different from the rest. 

gallery_19191_2362_99401.jpg

Thank you. These 2 pics are of one of the rudist fragments I have from the NSR.

301F0150-8C94-464C-838E-BEEBED5D3711.thumb.jpeg.e07dd4a31db91de8267353c94a39a249.jpeg

Top down view I think.9A2873DB-B19A-45E6-88C0-A13E01B7BF5F.thumb.jpeg.20b3fe921159341f0d6b4704e3600769.jpeg

 

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JarrodB
3 hours ago, KimTexan said:

Thank you. These 2 pics are of one of the rudist fragments I have from the NSR.

301F0150-8C94-464C-838E-BEEBED5D3711.thumb.jpeg.e07dd4a31db91de8267353c94a39a249.jpeg

Top down view I think.9A2873DB-B19A-45E6-88C0-A13E01B7BF5F.thumb.jpeg.20b3fe921159341f0d6b4704e3600769.jpeg

 

That's the kind I most commonly find at NSR

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