It is rare that you can ID a loose crinoid stem segment to the genus it is from but some forms are very distinct. Today's example of that are some stem sections from the crinoid Doloatocrius sp. What makes the stems unique are periodic growths that form a wider ring than the rest of the stem, and also have vertical extrusions at 120 degree intervals. The extrusions look a little like "fins"
The specimens shown below were sent to me as part of an trade with Mike P. and come from the Jeffersonville limestone near Louisville, KY. I did some research and cannot find any examples on the internet that show these stems in life position with a calyx attached. Also, in one of my previous blog entries I have a note with similar specimens found in Arkona, Canada that they belong to Megistocrinus sp. crinoids. That note may or may not be correct as I have seen pictures of stems attached to Megistocrinus nodosus calyx that do not show the "wing" like growths, just the thicker ring.
So for now I will keep the current label of Doloatocrius sp. until I can positively confirm otherwise.
Specimen #1
Specimen #2
Specimen #3
I received these specimens in an trade with Mike P. and they come from the Jeffersonville Limestone near Louisville, KY and is dated to the Devonian period (Eifelian stage).
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