Gen. et sp. indet. Posted October 14, 2016 Share Posted October 14, 2016 I find this arrangment of crinoids' parts interesting. Do you think this one could be articulated and the calyx hidding somewhere inside the rock? So far I was only finding disarticulated columnals and pluricolumnals, and no calyces. Palaeozoic, postglacial Pleistocene deposits, Poland. Link to comment Share on other sites More sharing options...
tmaier Posted October 14, 2016 Share Posted October 14, 2016 I believe that item with the circular arch IS a cross section through a calyx? That doesn't seem to have columal segments to me, and seems to be a sectional cut through plates. And I see what looks like a pentagonal plate, lower center in the first photo, and lower right on the second photo. Likely part of a calyx. Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted October 14, 2016 Author Share Posted October 14, 2016 Great! Thank you. Link to comment Share on other sites More sharing options...
tmaier Posted October 14, 2016 Share Posted October 14, 2016 This may damage your fossil, or might expose it better, use with caution... Try brushing with vinegar and a soft toothbrush. You might find that the matrix crumbles away and exposes more of your fossil. Worst case... it eats more of your fossil and leaves the matrix. Another bad situation is when it eats the details off the exposed fossil. You can experiment and use with caution... Sometimes it works pretty well. NEVER leave it in the vinegar all by himself for long periods, that always leads to damage to the fossil. Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted October 14, 2016 Author Share Posted October 14, 2016 I'll try. Just for clarity - you were refering to these two elements? Could these be somehow parts of a single calyx? Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted October 14, 2016 Author Share Posted October 14, 2016 Could you mark the supposed pentagonal plate? I'm not sure of the element, as I see at least two-three possible on the slab and photos. Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted October 14, 2016 Author Share Posted October 14, 2016 Couldn't the circular element be a cross section trough a giant stem? Attached is mine Crotalocrinites(?) encrusted by Aulopora(?). BTW, I am very puzzled by the element inside this fossil. Link to comment Share on other sites More sharing options...
tmaier Posted October 14, 2016 Share Posted October 14, 2016 The crecent moon shape you show above is not segments, so I'm guessing it is a section through the calyx. Looks like plates. And I'm having trouble uploading images, but let me try it again... Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted October 14, 2016 Author Share Posted October 14, 2016 Oh, OK. Thank you! Link to comment Share on other sites More sharing options...
tmaier Posted October 14, 2016 Share Posted October 14, 2016 Arggg! To upload that image I had to turn off my script blocker, and then scripts from many sites came pouring in, and it locked up my browser. Took me 20 minutes to turn off the faucet. Anyway, these cross sections can be hard to interpret, but you have bits and pieces that look like more than just segments. It would be nice to try to free them from the matrix more. Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted October 14, 2016 Author Share Posted October 14, 2016 I'll try to do my best. Thank you for your kind help & I'm sorry to hear you had such problems. All the best. Link to comment Share on other sites More sharing options...
abyssunder Posted October 15, 2016 Share Posted October 15, 2016 I just jump in... In the consecutive pictures shown above (posts 5,7), there are the same structures ( as I think ) : Crinoid columnal/pluricolumnals (the second one) in transverse section with flower like lumens, respecting the five fold symmetry and a singular lumen condition. So, that strange-shaped "what it is" in the lumen space infilled with sediments, should not be part of the internal structure of the crinoid, but could be from a sclerobiont , such as Hederella, also present/visible on the surface of the second specimen. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted October 15, 2016 Author Share Posted October 15, 2016 Hederella? Great. The sclerobiont on the outside of the second specimen is very big, though, so I identified it as Aulopora. Link to comment Share on other sites More sharing options...
abyssunder Posted October 16, 2016 Share Posted October 16, 2016 Probably you're right about the dimensions. Unfortunately, I don't see any scale (scale bar) for measurements (in mm) of you specimens. In any case, the lumen is clearly defined, and what's inside, as I said, is not a part of the internal structure of a crinoid stem. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
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