crinoid1 Posted July 16, 2013 Share Posted July 16, 2013 (edited) Its the only Crinoid I saw that had branches off of it as it goes to the top. Is there any from other time periods that have that. There are definitely other crinoids that branch multiple times irregularly. This isn't what you have, but this is a crinoid that branches like that from the Upper Mississippian. The crinoid does indeed look very much like an Arthroacantha. Rhopocrinus probodiscialis Ste. Genevieve ls. (Lower Monteagle Ls.) Upper Mississippian Huntsville, AL Edit: Added last sentence Edited July 16, 2013 by crinoid1 I like crinoids...... Link to comment Share on other sites More sharing options...
crinus Posted July 16, 2013 Share Posted July 16, 2013 If the calyx goes into the rock, then it needs to be prepped for a positive ID. The stem does, however, look like an Arthroacantha stem. It even has the cirri coming off it lower down. That is typical of Arthroacantha. See this one off my web page http://www.crinus.info/crinoids/data/arthroa.htm I have never heard of an Arthroacantha from Pennsylvania. How close is the locality to the Maryland Arthroacantha locality. If it is Arthroacantha then it would be Devonan. I am not faimiliar with Pennsylvania geology so I can't help you there. Were the other crinoids similar? Even incomplete crinoids can help with the ID. Are any of the calyxes of the other crinoids better visible? crinus Link to comment Share on other sites More sharing options...
Petrified Posted July 16, 2013 Author Share Posted July 16, 2013 I have never heard of an Arthroacantha from Pennsylvania. How close is the locality to the Maryland Arthroacantha locality. If it is Arthroacantha then it would be Devonan. I am not faimiliar with Pennsylvania geology so I can't help you there. Were the other crinoids similar? Even incomplete crinoids can help with the ID. Are any of the calyxes of the other crinoids better visible? crinus Im 4 hrs North of Maryland. Im getting some more pieces today hopefully Ill find some better ones. Ill post pictures later. Definition of a fossil= Love at first site. Link to comment Share on other sites More sharing options...
Petrified Posted July 17, 2013 Author Share Posted July 17, 2013 Went back today hit different areas of the shale bed but didnt really find anything but this brachiopod fossil. We went back to the spot where the crinoids were and still found a couple small pieces. The Brachipod fossil was about 50 feet from area of Crinoids. Definition of a fossil= Love at first site. Link to comment Share on other sites More sharing options...
Shamalama Posted July 17, 2013 Share Posted July 17, 2013 So if you are in Ridgway, PA, in Elk County your have rocks that are dated from the upper Devonian to the Pennsylvanian in the immediate area of town. The tops of the ridges are capped with the Pottsville formation which will mostly be Sandstone with some thin beds of shale and possibly coal. Most of the town and rivers are in the Shenango to Oswayo formations which range from upper Devonian thru the Mississippian. It's all somewhat homogenous rock with mixed beds of sandstone and shale and difficult to locate a clean dividing point. On geologic maps it's all lumped into one group. If Crinus is saying it looks like an Arthroacantha then I'd believe him. Going with that logic the rock you found it in is likely upper Devonian in age as that is what Arthroacantha is restricted to. -Dave __________________________________________________ Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrain. - John McPheeIf I'm going to drive safely, I can't do geology. - John McPheeCheck out my Blog for more fossils I've found: http://viewsofthemahantango.blogspot.com/ Link to comment Share on other sites More sharing options...
hrguy54 Posted July 17, 2013 Share Posted July 17, 2013 Excellent find!!! Link to comment Share on other sites More sharing options...
Petrified Posted July 17, 2013 Author Share Posted July 17, 2013 So if you are in Ridgway, PA, in Elk County your have rocks that are dated from the upper Devonian to the Pennsylvanian in the immediate area of town. The tops of the ridges are capped with the Pottsville formation which will mostly be Sandstone with some thin beds of shale and possibly coal. Most of the town and rivers are in the Shenango to Oswayo formations which range from upper Devonian thru the Mississippian. It's all somewhat homogenous rock with mixed beds of sandstone and shale and difficult to locate a clean dividing point. On geologic maps it's all lumped into one group. If Crinus is saying it looks like an Arthroacantha then I'd believe him. Going with that logic the rock you found it in is likely upper Devonian in age as that is what Arthroacantha is restricted to. Theres no definite answer as to what time period this Crinoid is. The Crinoid needs prepped to verify a time frame. But yes I am leaning towards Devonian. Definition of a fossil= Love at first site. Link to comment Share on other sites More sharing options...
PennyT. Posted July 19, 2013 Share Posted July 19, 2013 So beautiful, good luck on your next trip. Link to comment Share on other sites More sharing options...
masonboro37 Posted July 19, 2013 Share Posted July 19, 2013 Splendid! Thanks for sharing. You are so fortunate to be able to find crinoids. Just cap's in my area. Process of identification "mistakes create wisdom". Link to comment Share on other sites More sharing options...
Missourian Posted July 19, 2013 Share Posted July 19, 2013 Beautiful crinoid. Context is critical. Link to comment Share on other sites More sharing options...
Petrified Posted July 20, 2013 Author Share Posted July 20, 2013 Thanks everyone I hit the shale bed again the other day and it seems that there isnt anything on left side of crinoid section. Im going to work my way to the right next time I go there. Definition of a fossil= Love at first site. Link to comment Share on other sites More sharing options...
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