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I have not posted in a while and wanted to share an amazing fossil that i collected in December of 2017. Sharks usually do not come to ones mind when discussing Illinois fossils. Many collectors are not aware that you can find complete shark skeletons. Illinois is fortunate to be one of the few places in the world to find complete Pennsylvanian aged sharks. The vast majority of these fossils are found within siderite concretions in the Mazon Creek deposit. These rare sharks are always found as immature individuals. Illinois also has limited exposures of black shale similar to the Mecca Quarry Shale of Indiana. This shale was extensively studied by Rainer Zangerl in the 1960s and 70s and is known for the variety of sharks that he uncovered. I have been collecting a small exposure of this shale for the past 20 or so years finding a variety of bivalves, crustaceans, nautiloids and occasional fish. Most of the fish are fragmentary and usually not well preserved. I have shared pictures of a few of the specimens I have collected in past posts. One of the most interesting fish that I have collected is a little known group of sharks called Iniopterygians. They are also referred to as flying sharks due to the unusual placement of the pectoral fins mounted high up on the shoulder. It is believed that these fins would have functioned similar to the fins in modern flying fish. They have large eyes, club like tails and very unusual tooth batteries. There are several described types mostly known from fragmentary remains. Since preservation in black shale is usually poor, most of the described specimens are x-rayed rather then prepped to help identify bones and bone structures. The specimens that I have collected have all been relatively small ranging from five to six inches. This new specimen is by far the largest and best preserved example that i have ever seen. The specimen measures a little over a foot in length. Due to the quality of preservation, I had a friend spend nearly 40 hours prepping out the fish. It appears to be quite a bit different from other examples that I have found. If anyone on the forum knows of any researchers who work with these sharks, please let me know. Enjoy!
So I am likely way off base with that guess, but today I cracked open yet another small nodule with a little (5-8mm size of the actual fossil) circular fossil in the middle. They appear to have small scales or sharp edges which made me wonder if they are some kind of seed or spore. Maybe even a fish scale? They came from the same site as my other Pennsylvanian finds (old Chieftain Mine in Vigo County, IN). I'd appreciate any insight anyone may have as to the identity of these fossils. -Andrew