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Hello, I recently acquired an Edestus Heinrichi jaw fragment and wanted to draw an illustration of the animal. But all the images I can find on internet are so weird though.... How could it feed with such a jaw? It's so different from what we see today....From what I have read, it either used it's jaw like scissors or kind of like a hammer (like the sawshark ??) ? Also, how can paleontologist know how to reconstruct such a weird animal, no full skeleton can be found since they are mostly made of cartilage.

I've been looking at the records of the Carboniferous Eugenodontid Chondrichthyan Edestus in Illinois (famously referred to as the coal shark) in Illinois and I've found that there are a large amounts of reports from Underground mines at Sparta and Coulterville, Randolph County Illinois. I also found a record from fossilworks.org simply listed as "Coal mines of western illinois" at the coordinates 38.7° N, 90.0° W. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&taxon_no=34453&max_interval=Carboniferous&country=United States&state=Illinois&is_real_user=1&basic=yes&type=view&match_subgenera=1 O. P. Hay. 1909. On the nature of Edestus and related genera, with descriptions of one new genus and three new species. Proceedings of the United States National Museum 37:43-61 I'm wondering what are the actual best pits and mines by Sparta and Coulterville Illinois to find Edestus fossils, which ones and either still open or (if closed) still accessible, what safety precautions should one take if fossil hunting in one of these mines or pits, and is Mecca Quarry on the Indiana-Illinois border a good place to find Edestus specimens?

Hey guys! As some of you may know I run a paleontology education program. I take real fossils to schools and libraries. I've been over the years collecting things to make a mobile pop up museum. All that being said... I've been wanting to make a display of fossils from really weird animals that we can find fossils of. So far I have an edestus tooth and finally got myself a Tully Monster today. I am having trouble coming up with ideas, and as I have dealt mostly with dinosaur fossils, I am hoping to have the help of some of my fellow forum members who have a broader knowledge base than I. It doesn't have to be something that you have for sale or trade, but I'm simply looking for ideas of actually obtainable fossils I can be on the lookout for. I'm starting to look for trilobites but am in over my head here too lol. Any ideas on anything would be an IMMENSE help. Thanks y'all!

Hi all, this strange piece came with a batch of edestus fossils that were found in a coal mine in Illinois. Have no idea what it could be, the front seems to be coated in black coal mostly while the back has what appears to be ridges. All I know about the location is it was found in a coal mine along with some edestus teeth that is Carboniferous in age. Hoping with some help to get to the bottom of this mystery.

Over the past year, I've become fascinated with the often bizarre fish and sharks of the Pennsylvanian. Fortunately, my home state of Illinois is a great place to hunt for such fossils. I've shared several of these in other posts before, but wanted to put everything together in one thread. Probably won't have much to post for a few months after this, but once summer rolls around, I should hopefully have plenty of new finds to share. I would say there are three major settings in which you can find fish fossils in Illinois: Mazon Creek, black shales, and limestone. I have not had luck at Mazon Creek yet, but hopefully that will change. So I'll start out with the black shales. These specimens, my first fish fossils, were collected in August 2019 from the Mecca Quarry Shale exposed at a clay quarry in Utica, IL. This shale directly overlies the Francis Creek Shale (i.e. Mazon Creek) at this location. The three specimens below are stomach ejecta from some kind of fish, and are composed mostly of partially digested fish scales. In addition, I found this very nice pair of associated acanthodian fin spines. The top fin has an area showing damage, possibly due to predation.

Our shark adaptation education program for elementary students follows up the Cladodonts with three of the craziest looking early sharks and three that we think kids will love learning about. The Eugeneodontid "sharks" may not be sharks but they are just too cool not to teach the kids about. Bizarre is interesting and I also love talking about evolutionary extremes. The best part of these next animals is that they each allow my son to really stretch out as an artist and create some weird looking creatures. The kids will learn that Edestus were large, predatory shark-like fish that are related to modern ratfish. We will quickly cover the tooth whorl which is where the term Scissor-tooth comes from. I have been reading theories as to how the teeth were used and I think it will be fun to discuss possible feeding methods with the kids. We will not spend much time on Listracanthus because there is not much information about them. I have seen them described as being eel-like and covered in the "feather" denticles. This is one that is really about the artwork so my son is the star with this species. Can not wait to see his finished rendition. I think the kids will really love Stethacanthus. I know it is a cladodont but we separate it in the presentation. The Anvil Shark is a wild creature. The anvil shaped, denticle covered spine, patch of spine on its head, and the whip-like projections from the pectoral fins are adaptations that are open to debate. Asking open ended questions with this species will be more fun than giving the kids theories. What do you think the spines were used for and what do you think those whips are all about? The kids will guide the presentation about Stethacanthus. While we wont be adding any additional Cladodont fossils any time soon, I do hope to add either Caseodus or Campodus to our collection before the end of spring. I like the Eugeneodontids as artistic subjects for my son so we will pick up more of these fossils as we progress. Our presentation fossils Pic 1- Edestus heinrichi. This is an Illinois coal mine fossil, dated to between 360-320 mya. Another personal favorite. These are not common and it is pretty cool to be able to show this one to students. Pic 2- Listracanthus. A "feather" denticle from the Pennsylvanian-Desmoinesian in Iowa. Not the best example as it is difficult to see but a good photograph will help. Still it is cool just to have the Feather Shark in the program ! Pic 3- Stethacanthus altonesis. One of the two teeth we have from the Caney Shale Formation in Oklahoma. Again, it is just too cool to have Stethacanthus fossils. I do not know how rare they are or anything but it is just such a freaky little creature.

@DSMJake sent me this beautiful Edestus jaw to prep and I got the chance to work on it today. After a week of relaxing in the prep lab, chilling with the phytosaur, it came out of the box looking like this: To all appearances, it is simply covered in shale and the prep would require some simple abrasion. But as we all know, appearances aren’t everything! Under a good portion of the shale was a pile of pyritized shells! So, I abraided what I could and set to work with the Micro Jack. After the shells were gone, it went back into the cabinet for some more abrasive. After the abrasive, I blew the whole thing off and scrubbed the leftover soda off with acetone. The broken end of the bone had some cracking to deal with so they got a bit of super glue and the whole thing received a good consolidation. Why the whole thing you ask? Under the shale, the bone is also pyritized and the teeth are cracked with some enamel on the serrations missing. In order to lock all that down and reduce the risk of eventual pyrite decay, the whole piece got 2 good coats of thin Vinac. All this took a grand total of 3 hours of work.

I was given a jar of fossil shark teeth by a friend who knows I use them in education. These were collected on beaches in Florida but some of unknown origin seemed to be mixed in with the lemon, dusky, and sand tiger teeth. As I went through the teeth, one really jumped out as soon as I saw it. It did not look like the rest of teeth and it looked very similar to the Edestus tooth I have in my collection. I can not say for sure but I honestly can not think of anything else it is. In the pictures, the top tooth is my Edestus. The bottom is the partial that appears to be an edestus. Anybody have an opinion on this ?