SilurianSalamander Posted September 9, 2022 Share Posted September 9, 2022 (edited) Found at work. Ordovician to Devonian. It tapers so it’s not a crinoid stem Edited September 9, 2022 by SilurianSalamander More info 2 Link to comment Share on other sites More sharing options...
Kane Posted September 9, 2022 Share Posted September 9, 2022 Looks crinoidal to me. 3 ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
Fossildude19 Posted September 9, 2022 Share Posted September 9, 2022 Cephalopod is the most likely answer here, I think. 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...
New Members The-Good-Earth Posted September 10, 2022 New Members Share Posted September 10, 2022 Ya I think the segments with taper is the key. I vote Cephalopod as well Link to comment Share on other sites More sharing options...
erose Posted September 10, 2022 Share Posted September 10, 2022 There are other echinoderms with tapering stems. Look at rhombiferans. 1 Link to comment Share on other sites More sharing options...
Mochaccino Posted September 10, 2022 Share Posted September 10, 2022 Is the cross-section visible? As @erose mentioned, rhombiferan cystoids tend to have tapering stems, and some crinoids do as well. Also a more specific locality info might help. Link to comment Share on other sites More sharing options...
SilurianSalamander Posted September 10, 2022 Author Share Posted September 10, 2022 No cross-section is visible. Ordovician-Devonian rock most likely, probably Silurian. Found alongside agatized corals and stromatoporids with the occasional brachiopod or crinoid bit. Waukesha Wisconsin, fox river park Link to comment Share on other sites More sharing options...
Mochaccino Posted September 13, 2022 Share Posted September 13, 2022 (edited) On 9/9/2022 at 8:09 PM, SilurianSalamander said: No cross-section is visible. Ordovician-Devonian rock most likely, probably Silurian. Found alongside agatized corals and stromatoporids with the occasional brachiopod or crinoid bit. Waukesha Wisconsin, fox river park The two things your specimen most reminds me of are 1. The stems of rhombiferan cystoids, such as Ordovician Glyptocystites: http://paleoportal.org/index.php?globalnav=fossil_gallery§ionnav=detail&submission_id=1492&taxon_id=60&last_section=taxon&printer_friendly=1 and 2. certain straight-shelled nautiloids, such as Dawsonoceras or Spyroceras: https://louisvillefossils.blogspot.com/2016/12/silurian-dawsonoceras-annulatum.html?m=1 https://louisvillefossils.blogspot.com/2012/01/spyroceras-cephalopod.html?m=1 Of which if it's Silurian-aged, Dawsonoceras may be a better match. Unfortunately I'm not knowledgeable enough to pin down the ID, but visually they are some possible matches. If it's Wisconsin I might lean towards cephalopod, since I'm not aware of any cystoids from that locality but cephalopods like Dawsonoceras apparently do occur there: https://cdm15963.contentdm.oclc.org/digital/collection/paleo/id/3331 Edited September 13, 2022 by Mochaccino 1 1 Link to comment Share on other sites More sharing options...
aek Posted September 14, 2022 Share Posted September 14, 2022 @SilurianSalamander It is the the lateral thoracic view of a Silurian Gravicalymene celebra. It's missing the cephalon and the rest of it has broken off and weathered away. The arrow on the left is where the cephalon broke off and the top arrow shows where the median axial lobes begin. 7 Link to comment Share on other sites More sharing options...
SilurianSalamander Posted September 15, 2022 Author Share Posted September 15, 2022 19 hours ago, aek said: @SilurianSalamander It is the the lateral thoracic view of a Silurian Gravicalymene celebra. It's missing the cephalon and the rest of it has broken off and weathered away. The arrow on the left is where the cephalon broke off and the top arrow shows where the median axial lobes begin. 100% agree. This makes the most sense with the texture outside of the main ridge. Thanks so much! Link to comment Share on other sites More sharing options...
Tales From the Shale Posted September 29, 2022 Share Posted September 29, 2022 That is a cool trilobite fragment. I really forgot how much you can find in Wisconsin by looking at gravel alone. 1 Link to comment Share on other sites More sharing options...
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