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Pennsylvanian LaSalle Limestone Unknown


connorp

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I found these bits in the LaSalle Limestone member of the Bond Formation (Pennsylvanian). They were in a huge boulder and I could not remove them unfortunately. No clue what they could be.

 

B9482242-5EB9-4B84-83FB-445BC3CADA6A.thumb.jpeg.a29b173b7e84bea9f356a033715ecb74.jpeg

 

Any thoughts?

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20 minutes ago, Peat Burns said:

How big is it?  If it's small, I guess "trilobit"

Forgot to bring my scale cube. The larger piece was ~2cm wide.

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trilobite pieces?

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3 hours ago, Herb said:

trilobite pieces?

That’s what I was guessing, but it didn’t look to match up with Ameura or Ditomopyge, which I believe are the only two trilobites reported from here. 

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Looks like there's more of it in the matrix. A little prep would probably go a long way towards ID. I want to know more! :D

 

 

Mark.

 

Fossil hunting is easy -- they don't run away when you shoot at them!

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59 minutes ago, Mark Kmiecik said:

Looks like there's more of it in the matrix. A little prep would probably go a long way towards ID. I want to know more! :D

I do too! I was just hoping someone would convince me it was interesting enough to go back and lug a giant boulder down a rock slope.

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4 minutes ago, connorp said:

I do too! I was just hoping someone would convince me it was interesting enough to go back and lug a giant boulder down a rock slope.

Hand prep in the field. So invigorating. So in-tune with nature. Or you can just let it weather a season or two.

 

 

Mark.

 

Fossil hunting is easy -- they don't run away when you shoot at them!

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35 minutes ago, connorp said:

giant boulder down a rock slope

Wrap it in duct tape for protection and give it a shove.:)

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Interesting! I have found some similar looking pieces there- they appear to be composed of calcite similar to the brachiopods found at that site, but they are always thin, flat and relatively featureless. Unfortunately, I have no idea what they are! I will take pictures of one I collected to share tomorrow. 

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Here are two angles of the piece I found- the first one shows there are two of the similar flat "shell" fossils near each other, possibly from the same origin. I actually didn't even realize this piece also preserved an impression of a curved surface as well as the shell. 

 

20190723_092404-1.thumb.jpg.0858c9d1f6f64bddd16d592cb658cee5.jpg

 

20190723_092336-1.thumb.jpg.bfcf26d422cc3bc3c96a8dfa0daaa9d3.jpg

 

If I had to guess, I would say that these and your find above are pieces of mollusk shell, whether bivalve or cephalopod, but I have not found any lines or ornamentation that would make it obvious. It's actually somewhat reminiscent of the Pennsylvanian finds @cngodles has been posting- the big mystery bivalves. I have found the La Salle Limestone to be full of these kinds of mystery bits and pieces. 

 

I would definitely say your find is not a trilobite, though- all of the trilobite pieces I have found have had quite smooth surface texture and been preserved in 3 dimensions, not squashed. 

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The last couple I found are likely the body chambers of larger Cephalopods. I wish I could say, yeah, three layers of shell material is this genus or that, but I don't know enough about it yet. And wow, that is some clean limestone (compared to my almost black limestone)

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Here are two more. The first definitely looks like a rugose coral, no clue on the species though, any thoughts? This was about the only time I was excited to see a rugose coral since I've read they're pretty rare from this site.

 

5d3c80bda818a_IMG_66512.thumb.jpg.c354d687c4e61ddfcde09e6c0cd3fa15.jpg  5d3c80c01da19_IMG_66522.thumb.jpg.8009e968f7a88f05514c593e0f75cd25.jpg

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And then there's this guy.

 

IMG_6653.thumb.JPG.2e006080059ba8e17a26d2c48c1a9530.JPG  IMG_6654.thumb.JPG.90efdfa6b4738860a17bcfdf2ff95b11.JPG

 

It's in the shape of an oval with a raised ridge down the middle. No clue what it could be.

 

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The horn coral might be something in the family Hapsiphyllidae, perhaps Zaphrentites, or Lophophyllidiidae, like Lophophyllidium. They usually need to be sectioned for proper ID unless there are very few species known for that formation.  I'd check the literature on the formation and see what's been recorded there.  The second piece could be a broken blastoid or a columnal of Platycrinites crinoid :headscratch:

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18 minutes ago, Peat Burns said:

The horn coral might be something in the family Hapsiphyllidae, perhaps Zaphrentites, or Lophophyllidiidae, like Lophophyllidium. They usually need to be sectioned for proper ID unless there are very few species known for that formation.  I'd check the literature on the formation and see what's been recorded there.  The second piece could be a broken blastoid or a columnal of Platycrinites crinoid :headscratch:

My first thought was part of a blastoid as well but there are none reported from here as far as I know. There are quite a few crinoids though so that’s a possibility.

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8 hours ago, Peat Burns said:

The horn coral might be something in the family Hapsiphyllidae, perhaps Zaphrentites, or Lophophyllidiidae, like Lophophyllidium. They usually need to be sectioned for proper ID unless there are very few species known for that formation.  I'd check the literature on the formation and see what's been recorded there.  The second piece could be a broken blastoid or a columnal of Platycrinites crinoid :headscratch:

Read through most of the literature I could find (which isn't much) and you were spot on – the only reported rugose coral is Lophophyllidium proliferum.

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  • 2 weeks later...

Here's another one I find this Monday. I apologize for the not great photos, I was having a hard time getting close enough since it's so small, around a half centimeter. I'm guessing (hoping) some kind of shark tooth? Not really sure since it's so small. I'm trying to see if there's more underneath but limestone is not easy to prep with a pin vice.

 

IMG_6696.thumb.jpg.6362cefe6d267b61f6420b5874f2cd26.jpg  IMG_6698.thumb.JPG.00c67d78a1d68e9fc60433b5e20e20ad.JPG

 

IMG_6700.thumb.JPG.ca632ae76d353b4fa9b19c5eb08f2b27.JPG

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On 7/23/2019 at 7:41 AM, Rockwood said:

Wrap it in duct tape for protection and give it a shove.:)

:heartylaugh:

'Those who cannot remember the past are condemned to repeat it.'

George Santayana

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Definitely a shark tooth! And that is a variety I have not found there myself, very nice. The pictures are a little blurry, but Orodus seems like a possibility- let's get some experts in here, though...

 

@Archie @Elasmohunter

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29 minutes ago, deutscheben said:

Definitely a shark tooth! And that is a variety I have not found there myself, very nice. The pictures are a little blurry, but Orodus seems like a possibility- let's get some experts in here, though...

 

@Archie @Elasmohunter

I was certainly quite surprised to find it. It was not found at the Orlando Smith St roadcut but the one west on IL71. The only reason I go there is for Composita specimens, and I never find anything else nice there. Just a bunch of broken brachiopods.

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Here is a picture of some other supposed Orodus teeth. Similar in shape to mine, but don’t appear to have as many “striations on the top.” I hope that makes sense, I am not familiar with shark tooth terminology.

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