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On my way out of town after a family gathering at Starved Rock State Park (it was packed like crazy with people, but I was still able to get a quiet hike in early Sunday morning with my mom. The food at the Lodge is not bad at all, also!) I made time to stop by one of my favorite sites, a roadcut near Oglesby, IL. This steep, talus-covered slope is known to produce generous quantities of brachiopods, as well as rarer shark teeth, cephalopods, echinoderms, trilobites and coral, among other things, primarily from the Pennsylvanian La Salle Limestone Member of the Bond Formation. 

 

With the wet weather this year plants had grown wildly over the slope, but there was still plenty of rock to explore. 

 

5d9c1219f1895_2019-10-0708_30_16.jpg.014710f4859884c72bf38fb118962867.jpg

 

I got out of my car, jumped over the little brook running through the ditch, and made my way up the slope. 

 

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As erosion slowly eats away at the bluff, fresh boulders fall away and expose new things. A large section had fallen last year, and at the top of the slope I saw another section perilously close to breaking away, so I steered well clear of it. Caution is definitely required at this site, especially because of the risk of rock fall near the overhang, but also the danger of slipping on loose rock and falling-  a good sense of balance is very helpful!

 

5d9c13aee3518_2019-10-0708_31_18.thumb.jpg.dce8dc1c65c31959d204cb7fd6427f3d.jpg

 

Working my way carefully along the cut I began to find some interesting things. First up was this hash plate- it doesn't look like much here covered in mud, but in the middle are some Archaeocidaris sea urchin spines, and it also features a number of crushed brachiopods, including some with spines, as well as crinoid stem pieces and other bits. I have started cleaning it up, so I will need to take a picture of it after I'm done. 

 

5d9c162e3408f_2019-10-0708_38_59.thumb.jpg.fd06791056926acdffab1758bb2982dc.jpg

 

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The next find was even more exciting-  tucked behind a piece of rock I found this partial Petalodus ohioensis crown just lying there- it's worn, but it cleaned up nicely. Petalodus is the only tooth I have found out of the matrix at this site, for whatever reason. 

 

5d9c16c3ee880_2019-10-0708_34_24.thumb.jpg.657d31671aca1ee6e4a6d16e57ff2f3c.jpg 

I also found a few examples of what appear to be large bivalves- maybe some type of Pinna? The first one was on a boulder too large to remove, so all I have is the picture:

 

5d9c17d77164d_2019-10-0708_33_03.thumb.jpg.589b1a2c25566c730d72a8ddfc59872b.jpg

 

The second one is more 3-dimensional and in a smaller chunks of rock so I could bring it home. 

 

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I also found a few more smaller shark teeth- first a small crusher tooth of unknown species:

 

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And then a complete mystery tooth- I can't see any enamel from this side, so it will definitely need to be prepped before I can figure it out. 

 

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The last find was the most exciting (and nerve-wracking). I noticed an intriguing sliver of black and white peeking out of a rather large rock- I thought,  perhaps another shark tooth?

 

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Unfortunately the rock was too big to carry down the hill, so I decided to smash it against a bed-sized boulder near the top of the slope in order to break it down to a manageable size. After a few hard smashes, I turned it around to try gripping the other side. I hit it one more time and it split, right where the tooth was! I could see a root exposed, but there was no crown in sight. I scrambled to look through the pieces of rock that had fallen and thankfully was able to quickly spot the rest of the tooth. It had split fairly cleanly and was almost all there- my second Petalodus of the trip, and my largest and most complete one yet!

 

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Even though I was only able to stay for about 2 hours, this was an extremely successful hunt. A beautiful day outdoors and a bounty of ancient life, what more could you ask for? I have started to clean and prep my finds and I will post more pics as they are ready. 

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Wow those shark teeth are spectacular. I'm hoping to get over there sometime next week when I'm home for fall break. Hopefully I'll have half the luck you did.

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fossilsonwheels
6 hours ago, deutscheben said:

The next find was even more exciting-  tucked behind a piece of rock I found this partial Petalodus ohioensis crown just lying there- it's worn, but it cleaned up nicely. Petalodus is the only tooth I have found out of the matrix at this site, for whatever reason. 

 

5d9c16c3ee880_2019-10-0708_34_24.thumb.jpg.657d31671aca1ee6e4a6d16e57ff2f3c.jpg 

I also found a few examples of what appear to be large bivalves- maybe some type of Pinna? The first one was on a boulder too large to remove, so all I have is the picture:

 

5d9c17d77164d_2019-10-0708_33_03.thumb.jpg.589b1a2c25566c730d72a8ddfc59872b.jpg

 

The second one is more 3-dimensional and in a smaller chunks of rock so I could bring it home. 

 

5d9c18151b66e_2019-10-0708_39_51.thumb.jpg.5805a6c54c8e261c2da927d7b075d569.jpg

 

I also found a few more smaller shark teeth- first a small crusher tooth of unknown species:

 

5d9c18b97b71e_2019-10-0800_02_55.thumb.jpg.bd02d0bccfb5d4af2db1a6fea529cbe5.jpg

 

And then a complete mystery tooth- I can't see any enamel from this side, so it will definitely need to be prepped before I can figure it out. 

 

5d9c1920b0ec3_2019-10-0708_38_06.thumb.jpg.cc6ca51591ecbdedbc2d08383f6b93d9.jpg

 

I wonder if that crushing tooth might belong to a Holocephalian like Deltodus? I found a paper describing Deltodus angularis from the La Salle Limestone of the Bond Formation and that tooth has a surface similar to some Deltodus I have seen.

 

 

 

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Congrats on that Petalodus tooth. Great find! Looking forward to seeing it prepped out.

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Cool finds!  I'm looking forward to seeing them all cleaned up :popcorn::)

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7 hours ago, deutscheben said:

It had split fairly cleanly and was almost all there- my second Petalodus of the trip, and my largest and most complete one yet!

FOTM entry? You have a few weeks to get this one prepped and I sure would like to see it among the entries this month. ;)

 

 

Cheers.

 

-Ken

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12 hours ago, connorp said:

Wow those shark teeth are spectacular. I'm hoping to get over there sometime next week when I'm home for fall break. Hopefully I'll have half the luck you did.

Thanks! Best of luck to you, I am sure there are more teeth to be found. It would be great if we could plan a Fossil Forum outing someday, I think there are a fair number of us who have collected at this site.

 

11 hours ago, fossilsonwheels said:

 

I wonder if that crushing tooth might belong to a Holocephalian like Deltodus? I found a paper describing Deltodus angularis from the La Salle Limestone of the Bond Formation and that tooth has a surface similar to some Deltodus I have seen.

 

 

 

Yes, the Stephen Brusatte article on the teeth from this formation has been a very helpful guide. Deltodus seems like a good candidate, but crushing teeth often look so similar it's hard to tell. 

10 hours ago, Ludwigia said:

Congrats on that Petalodus tooth. Great find! Looking forward to seeing it prepped out.

 

9 hours ago, Monica said:

Cool finds!  I'm looking forward to seeing them all cleaned up :popcorn::)

 

4 hours ago, sharkdoctor said:

Great finds and report. Thanks for sharing!

Thanks all! I'm very glad I decided to make the stop. 

 

5 hours ago, digit said:

FOTM entry? You have a few weeks to get this one prepped and I sure would like to see it among the entries this month. ;)

 

 

Cheers.

 

-Ken

Thanks, I will definitely enter it this month, I think that should be plenty of time to finish prepping. :thumbsu:

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Cool finds and great report Ben and love that last tooth. This place always produces and hopefully more falls down over the winter. I just wish I was there when they cart off tons of rock after they tried to stabilize this road a couple years ago, I can only guess what was lost.

 

Lastly as you stated and I have in the past, this is a road cut that is not attended for smaller children, it is unstable not only with the side of the wall, but also with the steep, loose scree that you have to ascend.

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23 hours ago, deutscheben said:

Working my way carefully along the cut I began to find some interesting things. First up was this hash plate- it doesn't look like much here covered in mud, but in the middle are some Archaeocidaris sea urchin spines, and it also features a number of crushed brachiopods, including some with spines, as well as crinoid stem pieces and other bits. I have started cleaning it up, so I will need to take a picture of it after I'm done. 

 

5d9c162e3408f_2019-10-0708_38_59.thumb.jpg.fd06791056926acdffab1758bb2982dc.jpg

 

How do you differentiate between brachiopod spines and urchin spines? I have found quite a few small spine-looking fossils in these rocks but never knew what they were.

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DPS Ammonite

@connorp

 

Urchin spines are solid, are composed of single calcite crystals and have good cleavage as long as the calcite is not replaced. Urchin spines have rounded ends where they attach to the test and often have surface decorations including spines.

 

Brachiopod spines are hollow, often curving and do not have regular surface ornamentation.

 

See some of my brachiopod spines: 

52B432E6-343A-4777-949E-9952CEC3DEE2.jpeg

 

Fossil urchin spines from Wikipedia:

1DD3A3D3-FFF4-45AB-93F8-4E5D70E71A5D.jpeg

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@DPS Ammonite covered everything I was going to say. The preservation on the layer where I found the urchin spines is not great, with the fossils crushed and worn, so the most apparent differences here are the serrations or ornamentation on them, and their straightness, as well as a fairly uniform thickness. The brachiopod spines are relatively smooth, of varying lengths and thickness, and curved to some degree. 

 

Here are shots of some of the urchin spines after I cleaned all the mud and dirt off- it is more apparent under magnification, but you can somewhat see the regular bumps on them.

 

5d9de36a4381c_2019-10-0908_29_28.thumb.jpg.1d825447b8cc637adeb95fe1e5fb8e57.jpg

 

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For comparison, here is a brachiopod with attached spines I found in the same layer on an earlier trip- note the crushed preservation versus the inflated preservation typical for most brachiopods in the limestone here:

 

5d9de413984f4_2019-10-0908_31_55.thumb.jpg.2e2d0cf68554a5a12861af5b748ff165.jpg

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  • 3 weeks later...

Really nice finds and photos. 

Thank you. :)

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7 hours ago, Sasquatch1112 said:

What side of the road it did you find the    Shark teeth?

The roadcut pictured here is only on one side of Orlando Smith Road- the two-sided cut is a little ways further east on Illinois 71, although one member here did find a shark tooth there as well, I believe. 

 

1 hour ago, Tidgy's Dad said:

Really nice finds and photos. 

Thank you. :)

Thanks!

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37 minutes ago, deutscheben said:

The roadcut pictured here is only on one side of Orlando Smith Road- the two-sided cut is a little ways further east on Illinois 71, although one member here did find a shark tooth there as well, I believe. 

Yes, I did. It was tiny though, only 1-2mm in width. I only found it because I just sat down and dissected a meter by meter patch of fallen rock on the ground for over an hour. Kind of a miracle I found it. The roadcut discussed here is definitely better for shark material. Really the only reason to go to the one further east is if you want to find a bunch of Composita brachiopods, most other stuff there is poorly preserved.

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