Wrangellian Posted October 18, 2018 Share Posted October 18, 2018 Herein I plan to post pics of my modest collection of Mazon Creek fossils, but first a question. I found this nice little map in a paper by LoBue (2010) of the general Mazon Creek area, showing the location of the numbered mines/pits. Could any of you who know the area and the fossils explain in a nutshell which areas produce the Essex Fauna and which produce the Braidwood Fauna (or flora - maybe I should say 'Biota')? I know Pit 11 is the main source of Essex fauna (Essexella etc.), but is it the only place Essex fauna occur, and those other pits produce only Braidwood biota? Are they relatively exclusive of one another or is there some crossover? I work best with maps, so if anyone can annotate the map to make things clearer, please do. Also I'd like to know where the county lines are on this map. In the following fossil pics, I have incomplete info as they all came from dealers, auctions and such, I've never been able to collect the site myself, so the info I receive is typically incomplete and sometimes wrong. If anyone could narrow down any of the location info for any of the fossils, I'd appreciate it, and please correct anything that is incorrect! 3 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 I assume all fossils are from the Francis Creek Shale Member or the Carbondale Formation, unless someone can set me right on that? - Desmoinesian stage (Moscovian or Westphalian D) First, here's my recently acquired Macroneuropteris scheuchzeri (sp?) with 'hairs' and a sinuous trace fossil (Cochlichnus anguineus), that some of you have seen in the 'Mailbox' thread: Hairs are visible in part and counterpart (same hairs on both sides, it appears). As for location, I don't don't know which pit it might be from. 10 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 This one was ID'd as Palaeocaris typus (shrimp), from "between Braidwood and Morris, IL". I do need to figure out a better photog setup to get the fine details of fossils like this.. This was taken under full sunlight but I still can't get all the details I can see in person. Failed to include scale but the nodule is about 44mm long. 9 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 (edited) This one was ID'd as Reticulomedusa greeni, from Pit 11: Correction: Essexella Edited October 19, 2018 by Wrangellian corrected ID 6 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 Two worms - Astreptoscolex anasillosus, Pit 11? 8 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 Worm: Fossundecima sp? Pit 11? Unfortunately no counterpart to this one. Are those jaws I can see in the 2nd pic? Hope that can help with the proper ID. 5 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 (edited) Acorn worm: Mazoglossus remsdelli, Pit 11: Correction: probable coprolite Edited October 19, 2018 by Wrangellian corrected ID 4 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 (edited) Two worms: Left: Pieckonia helenae, Pit 11 Right: unknown Correction: both Didontogaster Edited October 19, 2018 by Wrangellian corrected ID 7 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 Multiple small Essexellas, Pit 11: I need to get another pic under different lighting for this one. All for now, until I get pics of the rest. First I need to figure out a good system with the right lighting/etc to do these justice, and that is easier on my back! 3 Link to comment Share on other sites More sharing options...
Heteromorph Posted October 18, 2018 Share Posted October 18, 2018 Can't help, but nice Mazon specimens. Link to comment Share on other sites More sharing options...
Nimravis Posted October 18, 2018 Share Posted October 18, 2018 My 2 cents and @RCFossils and @fiddleheadcan help more, but all of the Fauna appears to have come from Pit 11, this is just from the look of the concretion. Concretions that come from the actual river / creek look different than those from the Pit. The Macroneuropteris could have come from Pit 11, but I would bet that it came from some other area. I would probably rule out Pit 4, just because of the preservation. Pit 4 does from time to time produce nice ferns for me, but if it came from an older collection, it might have come from Dresden Lakes and I forget what that Pit was. As far as Essex Biota, Pit 11 and the strip Mine in Braceville are a yes. I know that Pit 4 is made up mainly of Braidwood Biota, but I did find my Eurypterid there and I know the area across the street that I always call “Across from Pit 4” Also contains both Essex and Braidwood biotas. Recently I found 1 Essexella asherae Jellyfish in a bucket of concretions from there, but I am not positive if it did not fall in from another bucket. I believe that Pit 4 was near the boundary of Essex and Braidwood biotas And storm surges, etc. could have moved marine Fauna into the freshwater. Soneone more knowledgeable about the general layout can correct me if I am wrong and I have seen maps in the past that had boundaries, I just cannot locate one at this point. BTW- love your fossils. 7 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 18, 2018 Author Share Posted October 18, 2018 Thanks Ralph, that helps. Hopefully those you summoned will come thru with more info. If I can figure out a better photo setup I'll make some of these look even better... There is detail in that shrimp for instance that I haven't quite captured. 1 Link to comment Share on other sites More sharing options...
Nimravis Posted October 19, 2018 Share Posted October 19, 2018 I took a pic of your map and these boundaries should be pretty correct- it is hard to make that line with my finger on an I-Phone. I found a reference to it in Jack's @fiddlehead book "The Mazon Creek Fossil Flora", if you do not have it, you should get it and his book on the Mazon Creek Fauna. Link to comment Share on other sites More sharing options...
Wrangellian Posted October 19, 2018 Author Share Posted October 19, 2018 Thanks. The book would no doubt be good to have but in the meantime I hope to glean the basic essentials here (not to go into too much detail). Which of the other pits can still be collected or have produced fossils in the past that we might see on the market? All of them? Link to comment Share on other sites More sharing options...
Nimravis Posted October 19, 2018 Share Posted October 19, 2018 I have never really seen Pit designations on Mazon Creek fossils when they are sold on the internet, and I believe all of the Pits have been developed with the exception of Pit 11 and the Creek itself Link to comment Share on other sites More sharing options...
RCFossils Posted October 19, 2018 Share Posted October 19, 2018 As a general rule of thumb, Pit 11 is the primary source of Essex fauna fossils. The second two most common sites would be the Braceville shaft mine spoils and Chowder Flats which has now been developed into a subdivision. Pits 13 and 15 are also sources of Essex fossils but are rarely collected do to the lack of exposures and low yield of fossils within the concretions. I have a friend who has collected Pit 15 for years. This was a slightly deeper water environment. Some of the animals preserved can be larger then what you can typically find at Pit 11. While the fossils can be spectacular, unfortunately the vast majority of the concretion are devoid of fossils. My friend has commented that on average, he has to collect a 55 gallon drum full of concretions to find one collection worthy fossil. Also many of the hills that used to produce have been leveled. Since the division of many of the other Pits skirt along the Essex/Braidwood borders, you do occasionally find Essex fossils in Pits 1, 4 and I have seen a few from the Mazon Creek as well. There was also a site in Western Illinois near Astoria named the Sun Spot Mine that produced Essex fossils. 5 Link to comment Share on other sites More sharing options...
RCFossils Posted October 19, 2018 Share Posted October 19, 2018 I would agree that your Neuropteris is from the creek. Not sure of the location of your Paleocaris but it is a nice specimen. Your Reticulomedusa is an Essexella The next 2 worms both appear to be Didontogaster I would agree that the next one is most likely Fossundecima and yes those are the jaws that you are looking at. They are usually well preserved. I think the next specimen might be a coprolite. From the picture, it does not appear to be an acorn worm. The next 2 worms also both appear to be Didontogaster. They are the most common Polychaete found at Pit 11. I would agree that the last specimen is a multiple Essexella. 3 Link to comment Share on other sites More sharing options...
Wrangellian Posted October 19, 2018 Author Share Posted October 19, 2018 10 hours ago, RCFossils said: I would agree that your Neuropteris is from the creek. Not sure of the location of your Paleocaris but it is a nice specimen. Your Reticulomedusa is an Essexella The next 2 worms both appear to be Didontogaster I would agree that the next one is most likely Fossundecima and yes those are the jaws that you are looking at. They are usually well preserved. I think the next specimen might be a coprolite. From the picture, it does not appear to be an acorn worm. The next 2 worms also both appear to be Didontogaster. They are the most common Polychaete found at Pit 11. I would agree that the last specimen is a multiple Essexella. Thanks. Just to be clear: you think the Neuropteris is from Mazon Creek itself, in the upper left of the map? That's disappointing about the copro and especially the jellyfish, but that's what I get for not asking you before buying! I got both of those some time ago. 13 hours ago, Nimravis said: I have never really seen Pit designations on Mazon Creek fossils when they are sold on the internet, and I believe all of the Pits have been developed with the exception of Pit 11 and the Creek itself I rarely see pit numbers on internet sales, either, but was unsure of whether that was because of carelessness on the part of the seller, or that they didn't know, or that the fossils are always assumed to be from Pit 11. Link to comment Share on other sites More sharing options...
Wrangellian Posted October 19, 2018 Author Share Posted October 19, 2018 11 hours ago, RCFossils said: The second two most common sites would be the Braceville shaft mine spoils and Chowder Flats which has now been developed into a subdivision. Where abouts are these locations on the map? I take it the Braceville mine is in the immediate vicinity of Braceville... Link to comment Share on other sites More sharing options...
Nimravis Posted October 20, 2018 Share Posted October 20, 2018 34 minutes ago, Wrangellian said: I rarely see pit numbers on internet sales, either, but was unsure of whether that was because of carelessness on the part of the seller, or that they didn't know, or that the fossils are always assumed to be from Pit 11. I really doubt that most people know where the concretions came from. I have bought some fossils in the past and the owner / seller had no idea where they came from. Link to comment Share on other sites More sharing options...
Nimravis Posted October 20, 2018 Share Posted October 20, 2018 31 minutes ago, Wrangellian said: Where abouts are these locations on the map? I take it the Braceville mine is in the immediate vicinity of Braceville... Chowder Flats is located in Morris, Illinois. The Braceville Shaft Mine is located at the cross roads of Interstate 55 and Braceville Road, Braceville, Illinois. Link to comment Share on other sites More sharing options...
Plantguy Posted October 20, 2018 Share Posted October 20, 2018 On 10/17/2018 at 10:45 PM, Wrangellian said: I assume all fossils are from the Francis Creek Shale Member or the Carbondale Formation, unless someone can set me right on that? - Desmoinesian stage (Moscovian or Westphalian D) First, here's my recently acquired Macroneuropteris scheuchzeri (sp?) with 'hairs' and a sinuous trace fossil (Cochlichnus anguineus), that some of you have seen in the 'Mailbox' thread: Hairs are visible in part and counterpart (same hairs on both sides, it appears). As for location, I don't don't know which pit it might be from. Nice collection! Especially have loved seeing these guys for a very long time and with a trace on yours to make it extra special! Regards, Chris Link to comment Share on other sites More sharing options...
Wrangellian Posted October 20, 2018 Author Share Posted October 20, 2018 47 minutes ago, Plantguy said: Nice collection! Especially have loved seeing these guys for a very long time and with a trace on yours to make it extra special! Regards, Chris Thanks Chris. I'm happy with this one - it looks better than it did in the sale pic (though I could tell it had a stain or two, which luckily washed off), and has a couple chips missing but between the two halves it is complete. Link to comment Share on other sites More sharing options...
Wrangellian Posted October 20, 2018 Author Share Posted October 20, 2018 4 hours ago, Nimravis said: Chowder Flats is located in Morris, Illinois. The Braceville Shaft Mine is located at the cross roads of Interstate 55 and Braceville Road, Braceville, Illinois. So Chowder Flats is across the Illinois River from the main pit areas? Is it that 'pondy' area I can see right there in the town of Morris on Google Maps? Also, I can't find 'Braceville Road' on Google Maps... Link to comment Share on other sites More sharing options...
Nimravis Posted October 20, 2018 Share Posted October 20, 2018 Sorry some places call it Braceville Road, others Division. Here it is- 1 Link to comment Share on other sites More sharing options...
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