Bonehunter Posted May 17, 2021 Share Posted May 17, 2021 So.....I was splitting my last piece of Pennsylvanian stark shale member, between Winterset and Bethany Falls limestone from a 2x2' 2" thick piece, I found some cool conodonts, a lot of scolecodonts, and amassing a pile of split shale, when I came upon yet another listracanthus/fish spine, about 5-6cm in length and very slender (2-3mm in width). I have both positive and negative pieces (depicted here). I scan all of these to see the pattern, faint impressions of a wider segment (as seen in photo 6 ), and in this particular specimen noted the shiny black cracks and creases surrounding the fossil. I see this very commonly in shale (and my understanding is it reflects rapid cooling of heated material?). In addition however, I saw what simply appeared to be conglomerations of, for lack of a better term, "worms" (Circled in blue in photo 2 and red in photo 6). Now stay with me on this one! Under microscopic evaluation numerous ''nematode" shaped objects adjacent to the spine are present, measuring 0.3-0.8mm in length are noted. Most are broken but there are some mostly intact. Several demonstrate fine "annelid" rings, (denoted by arrows) but I don't think these are annelids? At first I thought the preservation was too good to be real, but I have denoted numerous impressions in the shapes of worms, even to the point of the "rings". In reviewing nematode and annelid taxa, I don't see any mouthparts to make these polychaetes, and found reference to "ringed" nematodes. I hope someone can confirm or tell me if these are something else. I have placed circles (blue and red) around the groups, and arrows on salient features of impressions and the worms themselves. Also labeled a couple more intact individuals with an "N", but most are broken. If this is a reasonable observation, then this is one of the coolest things I have ever found!!!!! Fingers crossed I am on the right track!!!....Worst case, it is a plant piece with adjacent plant nematodes, which are very common nowadays and worst worst case, I am totally off track . There are 13 photos, with some seemingly one image but if you look close, they are separate if that helps. as always, thanks all!!! Have fun with these and let me know!! Bone 3 Link to comment Share on other sites More sharing options...
Rockwood Posted May 17, 2021 Share Posted May 17, 2021 You need to rule out diatoms first I think. Link to comment Share on other sites More sharing options...
Fossildude19 Posted May 17, 2021 Share Posted May 17, 2021 @jdp Cropped and brightened: 1 Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "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...
Bonehunter Posted May 18, 2021 Author Share Posted May 18, 2021 11 hours ago, Fossildude19 said: @jdp Cropped and brightened: Thank you for doing that!!!....shoulda done that before sending!!! Bone Link to comment Share on other sites More sharing options...
westcoast Posted May 18, 2021 Share Posted May 18, 2021 Annelid tubes with possible 3D body preservation would be very cool, that last image is very interesting! You might need to get SEM images. Well spotted. 1 Link to comment Share on other sites More sharing options...
Bonehunter Posted May 18, 2021 Author Share Posted May 18, 2021 5 hours ago, westcoast said: Annelid tubes with possible 3D body preservation would be very cool, that last image is very interesting! You might need to get SEM images. Well spotted. Ahh yes I see it!!!....Soooooooo coool!!!. I would hazard to guess they're feeding on detritus from the dead fish/shark? Went back and forth on annelid vs nematode. Thanks for this!! Bone 1 Link to comment Share on other sites More sharing options...
Mahnmut Posted May 18, 2021 Share Posted May 18, 2021 Hi Bonehunter, I cannot help with the iID of these fascinatingly preserved critters, just wanted to add my thoughts on your observation of the cracks and creases surrounding the fossil: I think these are a sign of differential shrinking in general, not necessarily due to temperature change. For example sediment losing its water content during diagenesis and shrinking more than an embedded bone. Courios to read more about this find. Best Regards, J 1 Try to learn something about everything and everything about something Thomas Henry Huxley Link to comment Share on other sites More sharing options...
Myrmica Posted May 18, 2021 Share Posted May 18, 2021 Well these are pretty interesting alright. When I began reading the post, I was skeptical because of the low likelihood of nematode preservation, and the fact that almost all are very small, but then I saw the magnified photos. Some modern nematodes do have ring-like patterns on the outside of their cuticle, even though they are not segmented. Then again, the absence of recognizable mouthparts is not that diagnostic... Just double checking: do you find these within the rock or do they appear to be in/on cracks in the shale? 1 Link to comment Share on other sites More sharing options...
Bonehunter Posted May 18, 2021 Author Share Posted May 18, 2021 1 hour ago, Mahnmut said: Hi Bonehunter, I cannot help with the iID of these fascinatingly preserved critters, just wanted to add my thoughts on your observation of the cracks and creases surrounding the fossil: I think these are a sign of differential shrinking in general, not necessarily due to temperature change. For example sediment losing its water content during diagenesis and shrinking more than an embedded bone. Courios to read more about this find. Best Regards, J Ahh- thank you!- that makes sense!. I read about the "glassy" aspects of shale, but it was not a peer reviewed article- your comments make more sense!- Fascinating!!!- never thought I'd find something like this, but also you never will if you don't look Bone 1 hour ago, Myrmica said: Well these are pretty interesting alright. When I began reading the post, I was skeptical because of the low likelihood of nematode preservation, and the fact that almost all are very small, but then I saw the magnified photos. Some modern nematodes do have ring-like patterns on the outside of their cuticle, even though they are not segmented. Then again, the absence of recognizable mouthparts is not that diagnostic... Just double checking: do you find these within the rock or do they appear to be in/on cracks in the shale? They are in the rock the best I can tell; The impressions of the "worms" in the shale tells me they were there when the shale was "formed".....and exactly- "ringed nematodes" are not segmented.......at least modern ones Thanks for the look!!! Bone Link to comment Share on other sites More sharing options...
Mahnmut Posted May 18, 2021 Share Posted May 18, 2021 I just wondered about shale and heat. It confused me that in (non-geologist-)German schist and shale are both called "Schiefer". But only schist is metamorphic and thus altered much by heat. Well preserved fossils are therefore found in shale, but not in schist. Good we talked about it! Cheers, J 2 Try to learn something about everything and everything about something Thomas Henry Huxley Link to comment Share on other sites More sharing options...
connorp Posted June 2, 2021 Share Posted June 2, 2021 I can't help on the "nematodes", but the fish spine looks like an acanthodian fin spine. Link to comment Share on other sites More sharing options...
Bonehunter Posted June 2, 2021 Author Share Posted June 2, 2021 OK- THATS SO COOL!!!!!!! Now I need to research Acanthodian!- thanks so much!! Bone 10 hours ago, connorp said: I can't help on the "nematodes", but the fish spine looks like an acanthodian fin spine. Link to comment Share on other sites More sharing options...
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