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Went to Oglesby Illinois to explore a well known site last weekend. Took me awhile to partially scrub and organize these individual specimens. Some Composita brachiopods? Can't remember for sure. My favorite find (looks better in person) someone must have tried to bash it out of the rock, as it has damage from a hammer, when I had found it in the matrix. I think its a Neospirifer, and quite large at that. Shame it has that shell damage but still great regardless. And then finally these very common brachiopods named Echinoconchus. By far the largest brachiopods I've ever found, that last one was so large I was having difficulty framing it on the grid paper. The site is very overgrown there are a monstrous amount of insects, but I did just fine with bugspray and a dream. I also went after a rainstorm, the wet ground made it much easier to spot brachiopods around the area. A few more Neospirifers.

I am new to the forum but have been collecting fossils for many years and need help identifying ones that I am having trouble finding on internet please and thank you! The last one looks like a fish but maybe it’s just a rock that looks like one

I've had these fossils for years now, but I never could figure out what they exactly were. The first image is of what looks like a fern and the second I'm not sure of (both found on the Lake Michigan shoreline in Illinois). The 4 following pictures are of 2 fossils found on the Ohio River near Louisville, Kentucky on the Indiana side of the river. One looks very clam like, while the other looks more like what I am assuming is a crinoid? I can make out a small stem and small circular patterns on the opposing end. The last 2 pictures I am the most unsure of. It looks similar to the jellyfish nodule fossils of Mazon creek. I found it in Northern Illinois in Cook County.

I had this Mazon Creek arthropod open recently. It was collected from the Braidwood fauna (freshwater/terrestrial), so initially I thought this was just a tiny syncarid shrimp as they are the most common arthropod to find here. However looking at it closer, I'm not so sure and was hoping for a second opinion. In particular, the legs are short and spiny and do not look like shrimp legs to me, although I may be wrong. Here are images of the positive and negative sides of the "head", middle, and rear, respectively. I put "head" in quotes because I can't tell if this is the head of the animal, or if it continues more into the concretion. @RCFossils @Nimravis @Mark Kmiecik @deutscheben @stats @bigred97 @flipper559 Any thoughts are appreciated.

Found this guy today in northern Illinois, right near Wisconsin border. Any clue on what species it is?

Any ideas on these?

Does anyone know of the specific location of roadcuts in Oglesby Illinois? I heard of a large productive one, but haven't been able to locate it specifically. Thanks

An ID post for a similarly shaped object @Mark Kmiecik made last month reminded me of this Pennsylvanian concretion I found a while ago at an eastern Illinois spoil pile. It has a shape and texture suggestive of a piece of chondrichthyan cartilage as @fiddlehead had mentioned in the earlier post, although the pattern is not well-defined like it is in other cartilage finds I have made. Thoughts? I’ll loop @jdp in too while I’m at it.

The Francis Creek Shale in northeast Illinois is best known for producing Mazon Creek concretions. However, the shale itself also contains an extremely diverse and well preserved flora (and fauna occasionally). Unfortunately, the shale is extremely soft, and quickly weathers to clumps of clay. This makes collecting from the shale very challenging, and most collectors don't even bother trying. On a recent trip I found some fresh chunks of shale and decided to try and save some of the plants. Even working with fresh shale, it was still very hard to extract anything. Larger pieces crumbled easily, flat surfaces flaked as they dried, and some fossils were destroyed just by accidentally brushing a finger against them. These specimens represent what I was able to save. They have been sitting out for over a week now and seem stable as long as they are not handled, but only time will tell if they last. Crenulopteris acadica Crenulopteris subcrenulata Neuropteris fimbriata (seed fern pinnule) Lepidostrobophyllum lanceolatus (cone bracts) On the left is a fern I am unsure of, any thoughts are appreciated. On the right is Stigmarioides. I have not found many examples of this taxa in concretions but it seems fairly common in the shale. I think this is also Stigmarioides. Many of the scars are plugged with pyrite - it was bright gold when I first split the shale but oxidation has darkened it. Hopefully these will last, but if not I wanted to post photographs in case they don't.

How rare are phragmocones from cephlapods? Are they something you need to get into a quarry to find, or can you recover them out of roadcuts? This is for the Midwest, like Illinois, Wisconsin etc.

I found this skull in our field next to our house last week. It was being pushed up from the ground. The photo shows the front R side of the face w/ clear jawline, R eye socket & R side of a crest. I would like ID help, please. We are 1/2 hour south of the WI border. It was near a fossilized, partially opened egg & the limestone-encrusted skull of a juvenile lizard, among other fossils. There are volcanic rocks nearby & we believe that the interstate Rock River was considerably larger, covering our property & bringing those things south to IL.

I was lucky enough last week to be able to make my second donation to the collections of the Field Museum of Natural History in Chicago. This donation consisted of two Mazon Creek finds from the river itself, both collected on the I&M Canal outing last year. The first is an extremely rare tetrapod larva. The second fossil is an exceedingly well-preserved Orthacanthus tooth, featuring serrations in the cusp, a very rare trait for Mazon Creek teeth of this sort. It may prove to be complete as well. I was able to visit the museum to make the donation this time and it was an honor to go behind the scenes and talk to professional paleontologists about these specimens and Mazon Creek collecting. Thanks again to @jdp for helping make this possible!

Hi all! Found this fossil in my garden, in northern Illinois. I was also wondering how old it is too. Thanks a ton :)

I collected this trilobite pygidium in the Galena Group (Upper Ordovician) of Illinois. I don't immediately recognize it, especially since it is just a mold. It is fairly large. My best guess is Isotelus but I was hoping one of the trilobite experts here might have a better idea. Thanks for any help.

I recently found this bit of fish bone in the LaSalle Limestone of Illinois (Upper Pennsylvanian). Measures about 1cm in width. I know that tiny bone bits are tough to identify, but the surface texture on this one seems pretty interesting. I haven't found anything similar before. The positive is shown above, although I think the negative shows the surface texture better. Can anything be said about this? @jdp @RCFossils @deutscheben Thanks for any help.

Yesterday I finally made it out to one of my favorite hunting spots after (almost exactly) a year away. This road cut in La Salle County Illinois had been visited earlier this year (I believe) by @Nimravis, @aek and @connorp, but I really wanted a crack at it before summer fully kicked in. As I had been warned, it was already heavily overgrown, with poison ivy located intermittently across the slope. There were also mosquitoes in the shady areas and wasps in the sunny ones. However, with some delicate maneuvering I was able to avoid most of the hazards, with only some mosquito bites to show for it. I was at the site from 11:30 to 5:30 and the sun shone bright nearly the entire time, although thankfully an occasional breeze kicked up and cooled things off. Here is a sequence of the path up to the head wall, as you can see it quite brushy at the base of the cut. All in all, I would call it a successful day. I was able to find quite a few interesting mollusks, both gastropod, cephalopod, and bivalve, that I had not encountered before from this site, and a few trilobite bits as well. The real reason I keep coming back to this location, however, is the high-quality and diverse chondrichthyan fauna found here, and it did not disappoint. In addition to many tiny shark bits which may or may not prove to be worth prepping, I found a few larger specimens which I am hoping are all or mostly complete. The trip-maker was this beautiful Deltoptychius: I also shared the site for part of the afternoon with @TheSandStorm, who was making his first visit to the locale- it was a pleasure meeting him. I love seeing new folks getting out to explore and discover the wonders of the fossil world! I will share more pictures of my finds in the next post.

Today I too a quick run out to the Kane County Fairgrounds in St. Charles, Illinois to visit the Chicago Gem and Mineral Show that is held at this location every Memorial Day Weekend. The show runs today and tomorrow and it opened at 10 am. My wife and I arrived at about 9:00 am and sat in the car for about 40 minutes. It pays to get to this show early, because there are always a lot of attendees and by the time the doors open, there could be about 150 people in line. A few minutes after I took the above picture, the line snaked around the building towards the back. There is a $5.00 entrance fee for each adult and they give you a small gem stone and a door prize drawing ticket upon entering. There is one large area for retail sales to the left and a smaller retail area to the right. There also is a large wholesale area that sells larger quantities of rocks, etc. I was surprised that some of the usual vendors were not present at the show, I do not know if it is due to gas / hotels costs that are were high in our area. The show also has a nice Kids Corner with giveaways. They also run 3 different Silent Auction tables that close at different times. You can get some good deals on jewelry, fossils, rocks, etc. They have a number of nice displays, her was a quick one on a Mastodon. Here was my favorite- It was put together by our own @fiddlehead Jack Witry and contains a number of specimens from the Field Museum, including 1/2 of the holotype of Bandringa rayi. Sharks of Illinois- CONTINUED ON NEXT POST-

Last weekend I had the opportunity to spend a few hours collecting in a quarry in northern Illinois that exposes most of the Galena Group (Late Ordovician). There was lots of fresh rock to hunt through, and it was a good and productive trip. As usual, lots of gastropod molds were found. Hormotoma sp. Liospira sp. Sinuites sp. Lophospira sp. Subulites sp. Unknown gastropod. Looks like Liospira but appears to curl in the opposite direction. Brachiopods show up too. Most common are molds of what I believe are Rafinesquina (@Tidgy's Dad?). The inarticulate Pseudolingula iowensis is somewhat common. Specimens are almost always crushed and missing shell, but they usually have some shell preservation which contrasts nicely with the yellow matrix. Occasional bivalve molds are found. This one has calcite? crystals. Trilobite parts are uncommon, and the only species I've seen from this quarry is Thaleops, possibly Thaleops laurentiana. Here is a cephalon I found. Now for my favorite finds of the day. A partial specimen of the small receptaculitid Ischadites iowensis. Fisherites is very common at this site, but I had not come across Ischadites before. A partial conulariid. Judging by the visible cross section, the back side is present, so this should hopefully prep out nicely. And finally, what might end up being a complete trilobite. Not sure if there is any more buried, but it does look like at least some of the shell is preserved, so fingers crossed!

I live in Chicago and for a while I’ve been wanting to try Fossil Hunting in Mazon Creek. My first trip three weekends ago I tried to have myself prepared but still wasn’t quite sure what I was getting myself into. I hiked to the tipple area, there I had a really hard time telling rocks from concretions because especially in that area most of the rocks are covered in an orange rust. I collected 5 gallons of what I later realized were almost exclusively rocks. The trip was still worth it though because there were lots of these fast little lizards running around on top of the exposed coal, and I had never seen wild lizards in Illinois before. Since then, I’ve done a lot more research and went on two more trips. I mostly collected along the northern ridge of the southern section of Monster Lake. I spend nearly the entire time crawling on my hands and knees through thick undergrowth up and down ridges. I’m sort of used to off trail hiking like that so I wasn’t very bothered by the vegetation. For a beginner I think I’ve had good success, but I still have some questions about identifying the right kinds of concretions. In an ESCONI youtube video on Mazon Creek they mention that siderite plates and diagonal concretions are no good and should be left behind. Does anyone have any tips on how to better differentiate these? For the plates, unless it’s obviously thin I can’t quite tell. I’ve included pictures of examples of what I couldn’t quite tell were plates or not. And for the diagonals I’m honestly not sure at all. Other than that I’ve so far really enjoyed fossil collecting, and I intend to continue through the summer until I am either consumed by the undergrowth, or my limited freezer space creates a massive backlog. I’m lucky in that I haven’t gotten a single tick yet (and I check thoroughly). I treat all of my hiking clothing and equipment with permethrin and I wear both the Picaridin lotion and Deet spray. The bugs run from me. Here are some concretions that I wasn't sure if they were siderite plates or not. Here are some I was more certain about

I found this specimen in the Galena Group (Middle/Late Ordovician) of northern Illinois. Seems familiar but I can't place it. Any thoughts?

Should I preserve this. And, please tell me how I should preserve this.

Hello everyone! Today I ventured out to the Mazonia-Braidwood State Fish and Wildlife Area for my first time, and it was… something. This post is going to serve as both a journal of my day, and as a request for assistance as I try to figure out what exactly a concretion looks like. Once I got my permit outside the office (which is just down Huston Rd a bit from the IL-53 and Huston Rd intersection; this is for people like myself who struggled to find an address or location of the office), I headed to Mazonia south unit, where I went to fossil hunting site 3. There were not really any exposed rocks here, so I went deeper into the brush. I spent two hours picking up random rocks that looked remotely orange and red, until I realized that I was probably looking for the wrong types of rock in general. I had seen a ton of pictures online of concretions from Mazon creek, but all of them were of the fossils people found on the inside, which left me befuddled about what the outside looked like. I walked around until I found a place with cell service and planted myself on rock so I could watch a couple YouTube videos of people who had visited the area before. I learned a little about what I should be looking for, but I was still very confused. I managed to find the rock below, which looks vaguely like a fossil and gave myself some false hope, but I believe it’s probably just the way minerals formed on the rock that are deceiving: As morale dwindled, I made my way back toward the parking area and decided to walk a bit down the road. I found a neat little skull in a ditch as I was walking: As I kept going, I started stopping at some small exposures within a few feet of the road, and that is actually where I saw what I now understand to be the nodules I should be looking for. It was one of the two below: It made me feel a bit better that I found an actual concretion, as I went much of the afternoon without seeing any rock exposures. I have come to believe that fossil hunting site 3 may have a dearth of concretions, though I may be incorrect. Anyway, after finding the first concretion, I found a few similar rocks. However, I’m not entirely sure if they are potentially fossil containing material or if they’re just rock: They all have the dark red sections that I associated with iron, so I took them with. That is about the extent of what I grabbed that I thought were concretions, though I realize now that not all of those are even concretions. As I was wrapping up a mostly forgettable day, in the last roadside stop before my car, I came across this: I asked elsewhere on the interwebs and was informed that it might be a trackway, which I would think would be from an insect. However, if it is something else, please do let me know. Regardless, I was thrilled with this. I didn’t know what it was, but I did know it wasn’t something I had ever collected. In fact, today was the first day I have ever collected fossils from organisms that lived on land. It more than made up for the cold, gloomy weather and the disappointment I had experienced earlier. Just make sure to know generally what you should be looking for before you get there, unlike me. Now to my big question. How do I differentiate concretions from any regular old weathered rock? Are they typically round to some extent, as I see on others’ posts, or do they sometimes occur as jagged shapes? Are spherical rocks more likely to be regular rocks, whereas concretions are generally flatter in a dimension? I understand their shapes and sizes are diverse, but are there any patterns that tend toward a concretion over any a generic rock? As I finish up this topic, I do have one question about the two oval concretions I showed in my hand. Are the theoretical fossils inside the “egg” shape that lies inside the shell, or would they be on the outside of the egg shape? In other words, once I remove the rest of the shell from each of them, do I do the freeze-thaw cycles on the rock inside the shells? Thank you for reading and helping, and I apologize for all the questions!

Hello everyone! My name is Lily and I'm happy to be joining the forum. I think I may have found my first fossil! I don't want to get my hopes up but I'm pretty excited. Out of my 20 years on this Earth of picking up random rocks in hopes of finding a fossil, I think I finally did it. I found it in Southern Illinois about 30 mins from STL, MO while I was gardening for my grandma. I dug a shallow hole for the plant & hit the rock. I can try to get clearer pictures if needed. Let me know if you need any more information as well. I'd like to know everything you can tell me about it! Thanks so much

Today I drove 6 1/2 hours - 340 miles (Round trip) to meet up with about 20-25 other ESCONI ( Earth Science Club of Northern Illinois). This site visited was a shaft mine on private property and we were allowed to collect for 5 hours, making for a long day when you add in the drive time. I believe that the fossils found at this location are about 600,000 to 1 million years younger than the fossils found at Mazon Creek. If I am wrong, one of the Forum menders that were in attendance can correct me. As usual, I may miss a name, but here are some that I knew were present: @stats , @deutscheben , @flipper559 , @jdp . I had missed out on the trips to this location last year and really wanted to attend this year after seeing the pieces of bark that were found in the red dog shale that is found at this location as well as concretions. The red dog shale has the fossils baked into the shale as a result of a fire that occurred on the shat mine about 6 years ago. This pieces found are really pretty. This shaft mine was in operation from 1904 though 1946 and was owned by several different companies, including the Peabody Coal Company that ran the strip mining operation around Pit 11, etc. It was a hot day, first time this year we were in the 80’s and the wind was a constant 25 mph and gusts had to hit 35 mph. This post will be picture heavy and will most likely take a few posts. I will start with a lot of pictures of the area and the collectors, one I finish that, I will add pictures of my finds at the time that I found them. Most of my finds I did keep, since it was my first time there and I wanted a representation of the fossils found at the location. I know that some types of fauna can be found, but I only found flora, and most of that was bark, which I liked a lot more than ferns, etc. Now on with some pics- A pic of me- thanks @deutscheben