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Hey Folks, Here are a few whatsits from yesterday’s hunt. First, my gut tells me plant material?

'Morning, everyone. I appreciate all the input on my last post, which was an outstanding demonstration of the Venn diagram of photography, limited magnification, and apparently wishful thinking... Less of a mystery here -- I'm trying to ID this little (11mm) fella. I collected him in 2010 at the Mazonia-Braidwood South Unit. The ESCONI guide doesn't seem to have anything similar -- thoughts? Thanks.

A few nodules I need help ID with @Nimravis. Essex biota and found in Pit 11. Thanks! #1.) I think this is some type of worm? #2.) Thanks for the help! I may be adding some more in the next few days for ID

Hi, everyone, it's been a minute -- I hope y'all are well and that you and your families are healthy and safe. I'm required to say "y'all" since we moved to New Orleans last summer. Fantastic city, great people, but I won't be peeking in the Chesapeake or anyplace else on the East Coast again any time soon. Then, *this* all happened. During this lockdown, it occurred to me that I could finally get around to trying to identify some of the material I've had sitting in boxes for years (and I'll post a few others). But what do I find when I log onto the FF after ages? A positive gaggle of Mazon ID posts. Love it! I collected this little fish in 2010 from the South Unit at Mazonia-Braidwood. He measures a whopping 13mm from nose to tail. I've been poking around on the web but I'm having a hard time with the ID. It looks like he has two spiky fins sticking up from just behind his head (they're clearest in the last photo). My brain itches with knowing that I've seen this guy someplace before, but I just can't find him again. Thoughts? Thanks...y'all.

Ok. So, apparently I need my eyes examined... Thanks, everyone. Maybe I'll have better luck with invertebrates. I'll post more photos separately, but here's a preview:

This first piece is a Mazon Creek fossil from Pit 11. Any help appreciated !! The second one is from the Creek itself, could this be a "fiddlehead" @fiddlehead . Thanks for looking !! Thanks, Phil

I wanted to join the squad of great Mazon ID threads we have had in the last week. These two were found split on my opening day trip to Mazonia-Braidwood/Pit 11. I only found half of the first one. It doesn't look like much, and it may be nothing, but its worth asking! The second one was split, but both halves were present. It is much more clearly something, but I'm not sure what, as there are not any clear features, although it is preserved with good definition and a nice contrasting color.

Hey Folks. Heres another I’m wondering about. It looks like an example of diplocraterion, but I’m not certain. Thanks for the look.

Here’s another I’m not sure about. It may be nothing? Thanks for the look.

Hey Folks, Found today at Mazonia. Thanks in advance for your response. Arthropleura?

I have been looking into getting started collecting at Pit 11 in Mazon Creek within the Braidwood-Mazon State Park. I know that there are some forms I need to complete to collect at the site. From what I’ve found, the form isn’t even on the park’s website anymore and neither is the report that the form alludes to. Are these forms still valid? Where can I find them? Are there any other rules that I need to know?

Hi guys! Newbie here and finally joined so i could post this after our recent opening day trip to Mazon Creek, Mazonia-Braidwood and Pit 11. My daughter and I found this one and I can't tell if its nothing or something. Maybe an essexella asherae jellyfish? or maybe i'm dreaming. It was already split, we haven't done our freeze/thaw yet on the whole nodules yet. Seems we did manage to get at least two of the pieces that go together - could possibly have the last piece in the bucket still as we are still going through our haul, but after a preliminary look, I suspect this is all we have. I tried to get a few pics the best i could, but they now don't look as good as i thought. And I just read that using coins for scale is not a good idea - sorry. Hoping my Mazon experts out there will be more familiar with US currency, anyway. So - these are the same nodule from a few angles and one pic with the two pieces together. Any ideas? Or maybe it's nothing. I know i have a small one with annularia. This is one of the largest we found, so maybe it's just wishful thinking. After hours of looking at these things, i think i could see fossils in anything now. THANK YOU! (ok, now it's not letting me add my pics - too big.) I'll be back with the rest of them as soon as i figure out how to get the size down. Sorry!)

I'm wondering if anyone can identify some mazon creek fossils the first 3 I think are shrimp or molts The 4th I was told was a "dragonfly body" I'm not sure what to think about that and am wondering if there is anything identifiable as an insect Finally it's not an arthropod, but just a curious color difference I'd like help with

My granddaughter and I are coming to Chicago from 3-29 to 4-4. We’ve looked for Petoskey stones along the shores of Lake Michigan in Michigan, and found a few small fossils, but we don’t know how to hunt for them or what to look for or what equipment we would need. Any info would be helpful. We are looking into Mazon Creek, but a lot of what I’m finding is that it’s all picked over. Any other sites that would be good for two beginners? Thanks!

Hey guys, I braved the creek yesterday on the first day of hunting season at Mazon. It was a thrilling first time getting to hunt there. These of the surface finds were pretty interesting looking and were among many duds, so I'm wondering if anyone has any ideas as to their classifications. The rest of the lot is in the freezer so look for my thread on that in a bit More concretions in the following posts: Thanks for looking!

Does anyone know what this concretion is? It came from Mazon Creek and was listed as a Unusual Rock concretion fossil. I purchased it ten years ago and am hoping others like this have been found since then and a description determination has been made. Help.

Taking another look at an Annularia (I believe sphenophylloides?) I saw a curious pattern in the corner and I was looking for some help identifying it. I was thinking it could possibly be Artisia?

Last week I made my third annual pilgrimage back to the Chicago area to visit family, do a little fossil hunting, gorge myself on great ethnic foods and treat myself to some Chicago-style deep-dish stuffed pizza for my birthday--yum! I had hoped to pick up some more Pit 2 (Braidwood Biota) Mazon Creek nodules from Fossil Rock campground in Wilmington but sadly it is now closed and up for auction with the distinct possibility that it will never again allow fossil hunters to gather nodules from the spoil piles at the back of the campground. Instead, I figured on focusing back on the Pit 11 (Essex Biota) nodules in the Mazonia/Braidwood State Fish and Wildlife Area where I first had hunted nodules since learning about them several years ago. I had hoped on meeting up with some TFF members but unfortunately this turned out to be a busy weekend for them and we never managed to get out for a group nodule hunt. I did make it out to Mazonia/Braidwood for a couple hours of the weekend. Luckily, this location in Braceville is only a short 45 minute drive from where we were staying so it is quite convenient to pop over there. The weather report did not look good for Saturday afternoon and soon after we arrived the low clouds and mist turned to drizzle and then to rain and we were chased out with little to show for our efforts. We did a little better on Sunday and I have a small cache of nodules soaking in a bucket at the moment before their first freeze/thaw cycle on a shelf in my freezer. I had suggested to the TFF members in the greater Chicagoland area (including far western cities and extending into Wisconsin) that if there were other fossil hunting opportunities in the area that I might be able to replace Fossil Rock campground with some other novel (to me and my wife, anyway) location. Rob Russell suggested a small road cut in north central Illinois as a possibility but stated that a much more certain location would be the St. Leon roadcut in southeastern Indiana. We considered how we wanted to plan our week in Chicago and decided that Friday would be the best day for a roadtrip to Indiana. Google Maps (for some unknown reason) showed this trip as just under 4 hours. I figured that would be only an hour more than we normally drive to get to the Peace River here in Florida and that we could do it as a day trip. We got up early on Friday (easy to get out of bed with the prospect of fossil hunting ahead) and were on the road before 6am. Being reasonably close to the Summer Solstice and at a much more northerly than our normal South Florida latitude, the days were long and we were able to depart in daylight. We ducked under the southern tip of Lake Michigan and once in Indiana headed southeast on I-65 toward Indianapolis. Right away I could see that the Google Maps estimate of arrival time was optimistic. Large swaths of I-65 were under construction and there seemed to be as many large semi trucks on the road as cars. We stopped off along the way for a quick breakfast and continued to make steady progress toward Indianapolis. We had planned on stopping there because in my haste to pack for the Chicago trip I had forgotten to pack a long sleeve shirt. I have had more than my fair share of solar radiation as a kid spending my days shirtless and shoeless running around the country roads of northern Wisconsin with the local kids during my youth and now prefer to spend my time in South Florida covered up from the sun as much as possible. Rather than lathering up armfuls of sunblock I tend to prefer long sleeve shirts for their abrasion protection as much as their SPF. I set the GPS for the address of a Target store in Indianapolis as we had left the Chicagoland area before they were open. Unfortunately, we got the E or W prefix wrong on the street address and ended up some 16 miles away from the store. We managed to find a discount store in the area and after about 5 minutes of shopping (twice my normal preferred extent) I came away with my new "in the field" shirt for the extravagant price of $2.50. Back on the highway again and heading toward the town of St. Leon. We were making reasonable time (as best we could with the traffic and construction) but realized that 4 hours was a hopelessly unrealistic travel time. When I double-checked the distance I realized that it was around 280 miles and a 70 mph average speed would be needed to make this journey in the specified time. As that was the limit on the fastest parts of the highway we would not be arriving mid-morning as I'd originally planned. In the end we arrived for an early lunch in St. Leon where we (surprisingly) found vegetarian food at a restaurant called Skyline Chili. Chili they had--several large cauldrons of it bubbling away in the open kitchen area--but skyline? The only skyline visible in this open rural area was that shown in silhouette on their sign. Post lunch we headed north on Old State 1 till we saw the splendor of the extensive roadcut that I'd seen in Google Maps satellite imagery or in the trip photos of other groups that have hunted here before us. This roadcut through the 450 million year old Upper Ordovician deposits seems to have been an effort to minimize the slope of the highway running through its middle. We parked well off the road on the extensive shoulder near the drainage area and could hear the frequent trucks and cars go by. On their way up the incline we could hear the trucks shifting into low gear to climb the grade and the engine breaking of the trucks making the opposite trip. We were the only ones there, the sun was shining, the weather was pleasant and within minutes of parking the car we saw that the rocks around us were virtually carpeted with brachiopods and other fossils--it was going to be a good day. It had taken us 6 hours to get here (50% longer than originally estimated) but with the prospect of a new and exciting hunting opportunity, we couldn't be happier. For those who have not yet seen the roadcut at St. Leon here is what it looks like looking down the sloping highway with terraced slopes flanking the road. You'll notice the wide shoulder and the shallow drainage trough which make for safe parking well away from the traffic. The photo of the brachiopod slab right next to where we parked the car indicated a productive day was ahead of us.

Paleozoic insects can be extremely difficult for an amateur collector to identify. Partial specimens, poor preservation and outdated publications make it nearly impossible to identify most specimens to the species level. To further compound the problem, many species names are synonymous and no longer valid. In my future posts on Mazon insects, I will not attempt to identify specimens beyond the family level unless I have a firm identification. Geraridae are known from many Paleozoic sites around the world. The first Gerarus specimens were described in 1885 by Scudder from specimens collected from the Mazon Creek Deposit. While all Mazon insects are rare, they are one of the more commonly found types. Some of the defining characteristics are the four wings are similar in in length. The wings fold back over the thorax and abdomen.The prothorax is elongated and often times has large spiny projections. One interesting note is that it has been observed that the wing veination on Geraridae can be highly variable. It can even be different from wing to wing on the same animal! This has led to dozens of species being named. Many are synonymous and no longer valid. The largest recorded specimen size is 7.5 centimeters. I have one in my collection that is slightly larger measuring 8 centimeters. There has been much debate over the lifestyle of Geraridae. Current thinking is that they were not strong fliers and may be distantly related to crickets and grasshoppers. While Geraridae are known from Paleozoic sites worldwide, they are usually flattened and preserved as a thin film making study difficult. Mazon specimens can be found inflated exposing key structures not usually seen from other sites. Professor Jarmika Kukalova-Peck extensively studied Mazon Creek insects. She used Gerarus specimens from Mazon Creek to formulate her hypothesis of the origin of insect wings. The hypothesis is still debated and much more work needs to be done. This first specimen was collected from Pit 4 (Shadow Lakes). It has wonderful preservation and is the largest known specimen that I am aware of. Jarmila Kukalova-Peck studied this specimen and thought it might be a new genus. She also figured the specimen to determine various structures and wing veination.

There are 3 species of centipede described from the Mazon Creek Deposit. Mazoscolopendra is one of 2 described Scolopendromorphs. The second being Palenarthrus impressus. The main difference being Mazoscolopendra having 21 body segments and Palenarthrus having 23. It is interesting to note that while centipede translates to 100 feet, all known centipedes have an odd number of segments. Mazoscolopendra is essentially indistinguishable from modern day scolopendromorphs. Modern types have Front legs modified into fangs that inject venom into their prey. Some species are known to prey on birds, mice and even bats. It is assumed that Mazoscolopendra had a similar venom. A few modern types of Scolopendra are the only known aquatic centipedes. While Mazoscolopendra is found in both the Braidwood and Essex portions of the deposit, it is believed that it was strictly terrestrial. While some modern Scolopendridae can reach lengths of over 25 centimeters, the largest recorded length of Mazoscolopendra was around 5 centimeters. I do have a larger example in my collection that measures over 7 centimeters. Centipedes are a very rare component of the Mazon Creek Deposit. Based on the relative abundance study that I have referenced in previous posts, they make up approximately.002% of all Essex fossils. Out of approximately 230,000 concretions collected, 2 specimens were found. This first specimen was collected at Pit 11 and has been prepped to expose more of the animal.

This middle Pennsylvanian concretion from Mazon Creek (Francis Creek Shale), was discovered in the fall of 2013 in pit 2. Pill Bug (Pill Millipede) Phylum: Amynilnilyspes Class: Diplopoda Order: Amynilyspedida Amynilyspes wortheni

Just joint and wanted to get my first entry in. This middle Pennsylvanian concretion from Mazon Creek, was discovered in 2015 in pit 2, in an area I call Ivy Ridge thanks to all the Poison Ivy in the area. The finger near the top right should be where the shark emerged. I did not find this shark egg case variety posted. I hope this helps in future identification. Eventually I will be getting the measurement blocks. Shark Egg Case Phylum: Chordata Class: Chondrichthyes Palaeoxyris multiplicatum Horseshoe crab Phylum: Arthopoda Superclass: Chelicerata Class: Merostomata Order: Xiphosura Euproops danae

I had a few duds pop open yesterday but saw one had a tiny speck of something on it, no more than a millimeter long. I had my digital microscope out for other microfossiling activities and decided to take a look. Nothing super interesting, just a tiny plant fragment. But it did get me curious if anyone has done micropaleontology work on Mazon Creek material? I would think there would be quite a bit to explore, but that said I've never really seen the topic mentioned. The only microfossil I've seen discussed from Mazon Creek is a species of ostracod, but usually the only specimens you see are nodules containing hundreds of ostracods as they are readily apparent to the naked eye in that case.

This middle Pennsylvanian concretion from Mazon Creek (Francis Creek Shale), was discovered in the fall of 2013 in the Mazon Creek Heritage Site. Whip Scorpion Phylum: Arthropoda Class: Arachnida Order: Uropygi Geralinura sp.

Managed to stop in for a little Mazon Creek style Easter egg hunt when I was up in Chicago last June. Brought back maybe a gallon or so of concretions and I've been cycling them in my freezer (when I remember). I like to give them a bit of a (gentle) tap around the edges from time to time. This often helps the concretion to shed an outer layer or to coax a split that is nearly there and just begging to pop. As expected, I've had a number (the majority) of concretions open up to reveal a complete lack of anything at all within. The only thing that revealed itself to be of interest was this little concretion that measures 3.5 x 4.0 cm. I pulled out my copy of The Mazon Creek Fossil Fauna book and you think with that information at my fingertips that I'd be able to make a coherent guess as to the identity of this fossil but I am at a loss to match it up convincingly to any of the taxa described there. Hoping some of the members here with more experience can chime in. @Nimravis @RCFossils @stats @Mark Kmiecik