Misha Posted December 31, 2020 Share Posted December 31, 2020 Hello everyone, I have posted about this fossil before but I was not able to get it Identified. I have decided to create a separate topic for it because I am quite interested in if this is really what I initially thought it was. The fossil is from Eifel (Middle Devonian) and on one side there are a bunch of Crinoids columnals, but upon flipping it over I noticed this darkened branching structure on the rock, to me it looked very reminiscent of certain algae, although I have never seen anything like that from the Devonian so it's probably something else. So my question is: Is this really a fossil of any kind? Or is this something else that I am misinterpreting? Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted December 31, 2020 Share Posted December 31, 2020 Looks like a big bryozoan colony to me. Does it have signs of zooecia? 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Misha Posted December 31, 2020 Author Share Posted December 31, 2020 14 minutes ago, Tidgy's Dad said: Looks like a big bryozoan colony to me. Does it have signs of zooecia? Not that I can see, The area this covers has a smoother texture and is darker in color than the surrounding rock. Other than that there are no apparent patterns, texture or anything like that Link to comment Share on other sites More sharing options...
Rockwood Posted December 31, 2020 Share Posted December 31, 2020 Chondrites, or possibly planolites, trace fossil is my thought. 2 Link to comment Share on other sites More sharing options...
Misha Posted December 31, 2020 Author Share Posted December 31, 2020 8 hours ago, Rockwood said: Chondrites, or possibly planolites, trace fossil is my thought. That is highly plausible, The only thing that I would be unsure of is that aren't trace fossils generally different in shape while being consistent in color and texture to the surrounding rock? This piece is flush with rock around it, darker in color than the surrounding matrix. The traces I have seen show some 3d form to them, but this here is just flat against the rock. Link to comment Share on other sites More sharing options...
Misha Posted December 31, 2020 Author Share Posted December 31, 2020 I took some additional pictures as well as close-up shots of some of the branches, maybe these will be helpful: Link to comment Share on other sites More sharing options...
Misha Posted December 31, 2020 Author Share Posted December 31, 2020 Link to comment Share on other sites More sharing options...
Misha Posted December 31, 2020 Author Share Posted December 31, 2020 Link to comment Share on other sites More sharing options...
paleoflor Posted December 31, 2020 Share Posted December 31, 2020 Only algae I know of are Buthotrephis and Mosellophyton, which have been reported from several Devonian localities in the Eifel region (e.g. Schweitzer collection). However, the Devonian algae from the Eifel that I have seen myself (e.g. photo below, taken at Museum Devonium in Waxweiler, Germany) were all relatively "smooth" compared to the host rock, while the details on photographs you show here are quite "grainy" throughout. This could be due to preservation state, of course, but it is a noticeable difference. A trace fossil like Chondrites seems a very good alternative, especially since the same specimen also shows crinoid segments. 3 Searching for green in the dark grey. Link to comment Share on other sites More sharing options...
Misha Posted December 31, 2020 Author Share Posted December 31, 2020 15 minutes ago, paleoflor said: Only algae I know of are Buthotrephis and Mosellophyton, which have been reported from several Devonian localities in the Eifel region (e.g. Schweitzer collection). However, the Devonian algae from the Eifel that I have seen myself (e.g. photo below, taken at Museum Devonium in Waxweiler, Germany) were all relatively "smooth" compared to the host rock, while the details on photographs you show here are quite "grainy" throughout. This could be due to preservation state, of course, but it is a noticeable difference. A trace fossil like Chondrites seems a very good alternative, especially since the same specimen also shows crinoid segments. I just looked up Chondrites and it does look remarkably similar! That's what I'll label it as, seems much more likely than any of the other things I have been looking at. Thanks for the help! 1 Link to comment Share on other sites More sharing options...
Rockwood Posted December 31, 2020 Share Posted December 31, 2020 49 minutes ago, Misha said: That is highly plausible, The only thing that I would be unsure of is that aren't trace fossils generally different in shape while being consistent in color and texture to the surrounding rock? This piece is flush with rock around it, darker in color than the surrounding matrix. The traces I have seen show some 3d form to them, but this here is just flat against the rock. Color is a poor indication. The infill can be quite distinct or nearly identical to the matrix. Chondrites appear to be primarily tunneling structures. Those conditions would be less likely to have plate shaped minerals arranged in a manner that would create a plain of weakness than a surface (or near) feeding trace which may be similar. These may be sectioned to a greater degree as a result. 2 Link to comment Share on other sites More sharing options...
Misha Posted December 31, 2020 Author Share Posted December 31, 2020 1 minute ago, Rockwood said: Color is a poor indication. The infill can be quite distinct or nearly identical to the matrix. Chondrites appear to be primarily tunneling structures. Those conditions would be less likely to have plate shaped minerals arranged in a manner that would create a plain of weakness than a surface (or near) feeding trace which may be similar. These may be sectioned to a greater degree as a result. Thank you for explaining it to me! I am very unfamiliar with ichnology, I think that is the correct ID. Link to comment Share on other sites More sharing options...
Rockwood Posted December 31, 2020 Share Posted December 31, 2020 52 minutes ago, Misha said: I am very unfamiliar with ichnology, Maine is crawling with them. Link to comment Share on other sites More sharing options...
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