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HI all, I found this while searching the Bond Formation Pennsylvanian road cut in Oglesby, Illinois. Any Ideas? Also, Here is a bonus pic of a Peripristis semicircularis I am prepping out. There are a few fossils I am working on right now, but I plan to make a post of my trip once things are cleaned up. Thanks for looking!

Today, as I was unpacking some boxed up fossils, I noticed one of the Peripristis teeth I had collected last year looked a bit different. I then compared it to some of the photos I had taken and uploaded of it back in September when I submitted it to the FOTM contest. The tooth has definitely changed some color. When I prepped out the tooth, it had a much more vibrant white/ blue coloration to the tooth, especially toward the tip of the crown. My question is what causes this? Does oxidation change the color over time? Im not too knowledgeable with teeth, and I haven't observed this with other teeth I've collected before. September- Now- As found- before prep showing less red coloration

It's been a busy summer out here in Wisconsin, but fortunately I was able to make multiple trips out to Oglesby in Illinois. Here were some of the top finds. Perepristis semicircularis, found on my second trip. The chip on the top was from my unlucky Dremel stroke. The white dots on the left are not damage, but tooth coloration. My first and only connularid, of unknown affinity. I'm pleased to have this despite it being fragmentary. What I believe to be an ameura trilobite pygidium, nicely preserved. Composita argentia found a ton of these, but this rock contained a nice presentation of them. This nice complete large brachiopod. I'd give a name, but I've seen it called like three different names in other posts, so I'm not sure myself. A nice whole neospirifer, mostly whole anyways. Lastly something I wanted to show, it almost looks like a younger smaller version of those giant brachiopods like from image five. I have about 50 pounds of rock from Oglesby now, and most of that has yet to prepped, which my family is really happy about seeing in the garage I assure you.

So as the titles states "Mazon Creek Collecting or the Joy of Instant Gratification- Choose Wisely", that was my choice today, and I choose instant gratification. Even though I have not been out to Pit 11 this year, I wanted to find some fossils and not just concretions with the hope of finding something, plus I still have a lot of buckets to crack open, so I decided to collect some other Pennsylvanian fossils. I decided to stop by a road cut that exposes the LaSalle Limestone member of the Bond Formation and had a great day collecting in near 40 degree weather. It was very sketchy collecting today since the ground is not frozen, but it is also not thawed, so it is very slick in the none snow covered area and it can send you sliding to the bottom of the road cut as it did to me today- a nice controlled slide of about 20 feet. Here are only a few of my finds from today, after a short time I stopped taking pics. Here is a nice partial Peripristis Shark Tooth, I believe I found a couple other possible partial teeth, but I will check those out tomorrow. A few large Echinaria brachiopods- Many big Composita argentia brachiopods- A little Orthoconic nautiloid- Spirifer brachiopod- Linoproductus cora brachiopods- Juresania nebrascensis an Spirifer brachiopods-

On Saturday I posted pics from a Fossil Hunting Trip that I did the day before at a road cut in Ogelsby, Illinois.This area contains fossils from this formation- La Salle Limestone member of the Bond Formation (Missourian, Pennsylvanian) Unit 3. On of the pics that I posted was of something that I did not recognize and as always happens on the forum, someone responds with an identification. FF Member @Archie (Sam) stated that it was a Peripristis shark tooth and later stated that it was the lingual view. I then did some searching on the internet for pictures of this type of tooth and Sam was right on. During my search, I also came across an article titled "Pennsylvanian (Late Carboniferous) chondrichtyans from the LaSalle limestone member (Bond Formation) of Illinois, USA. This paper was written by Dr. Stephen L. Brusatte , who is a Chancellor's Fellow in Vertebrate Paleontology at the University of Edinburgh- (He grew up in Ottawa, IL. a town very close to Oglesby). Dr. Brusatte is an American Paleontologist and Evolutionary Biologist who specializes in the anatomy and evolution of dinosaurs. I found his e-mail address and late last night I e-mailed him pictures of this tooth and he responded early this morning and confirmed what Sam had stated. He further stated that "shark teeth are quite rare in the Pennsylvanian rocks of the Oglesby area". Sam, thanks again for helping me out with this ID.