New Members laurachristine1970 Posted December 23, 2023 New Members Share Posted December 23, 2023 First and foremost, I’m new to fossil collecting and what an amazing journey it’s been. I live in Lincoln County Missouri near the Cuivre River and have found some amazing fossils. It seems the creek that flows into the Cuivre is CHOCK FULL of “death plate fossils” (sorry if I used the wrong terminology). Being a “newbie” I have many ID’s to request. I will start today with my newest find. 1 Link to comment Share on other sites More sharing options...
Al Dente Posted December 23, 2023 Share Posted December 23, 2023 It is a steinkern of a horn coral. This is the sediment that surrounded and filled the coral, the actual coral has dissolved away. 1 5 Link to comment Share on other sites More sharing options...
Fossildude19 Posted December 23, 2023 Share Posted December 23, 2023 I agree with Rugose coral steinkern. Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 IPFOTM -- MAY - 2024 _________________________________________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
DPS Ammonite Posted December 23, 2023 Share Posted December 23, 2023 (edited) This is an external mold (probably now silica) composed of sediments that filled the top of a horn coral also known as the calyx of a coral. The “fins” are exterior molds of the septa. Steinkerns are internal molds such as the hardened sediment inside a closed bivalve. https://fossillady.com/tag/helliophyllum-facts/ Edited December 23, 2023 by DPS Ammonite 2 My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Al Dente Posted December 23, 2023 Share Posted December 23, 2023 27 minutes ago, DPS Ammonite said: This is an external mold (probably now silica) composed of sediments that filled the top of a horn coral also known as the calyx of a coral. The “fins” are exterior molds of the septa. Steinkerns are internal molds such as the hardened sediment inside a closed bivalve. From here-https://www.researchgate.net/publication/237837061_Notes_on_taxonomy_and_taphonomy_of_two_Upper_Maastrichtian_Upper_Cretaceous_scleractinian_corals_from_Limburg_The_Netherlands Link to comment Share on other sites More sharing options...
DPS Ammonite Posted December 23, 2023 Share Posted December 23, 2023 11 minutes ago, Al Dente said: From here-https://www.researchgate.net/publication/237837061_Notes_on_taxonomy_and_taphonomy_of_two_Upper_Maastrichtian_Upper_Cretaceous_scleractinian_corals_from_Limburg_The_Netherlands If you take a horn coral (like the one pictured) and impress it into clay you get an external mold. A steinkern is formed in cavities that have no or minimal connection to the exterior. A calyx of a coral has a large connection to the exterior. 1 My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
DPS Ammonite Posted December 23, 2023 Share Posted December 23, 2023 Here are pictures of two of my Mississippian horn corals (same genus?) that are part/counterpart or positive/negative. Photo 1 is looking down into the calyx of a silicified horn coral. Note slit cavity known as a fossula marked as F and septa marked S. Photo 2 shows the silicified infilling, exterior mold, of a similar horn coral with prominent septa, (marked Sm), and a fossula, (marked with Fm). OP’s fossil is similar to this form of preservation of a horn coral. Note arrow points to gap where the calcitic coral dissolved away. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Al Dente Posted December 23, 2023 Share Posted December 23, 2023 1 hour ago, DPS Ammonite said: A steinkern is formed in cavities that have no or minimal connection to the exterior. we’ll have to agree to disagree on this one. Link to comment Share on other sites More sharing options...
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