Gen. et sp. indet. Posted September 21, 2018 Share Posted September 21, 2018 Ordovician or Silurian erratic boulder from Poland. It's not the first time I come across this type of fossil. Would you say these are bivalves or some big trilobites' pygidia? Link to comment Share on other sites More sharing options...
DevonianDigger Posted September 21, 2018 Share Posted September 21, 2018 All I see is geology here I'm afraid. Is there a specific spot you're referring to that maybe I am just not seeing? Jay A. Wollin Lead Fossil Educator - Penn Dixie Fossil Park and Nature Reserve Hamburg, New York, USA Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted September 21, 2018 Author Share Posted September 21, 2018 Oh, come on. It is a finely laminated (visible on the side of the specimen, not on the photographed surface) rock, and the fragment with growth lines is parallel to the laminae and embeded in one of them, and has some thickness. Link to comment Share on other sites More sharing options...
Kane Posted September 21, 2018 Share Posted September 21, 2018 I think I would rule out trilobite pygidium for this one as I'm not aware of any trilobite morphology that would have these striations in the sequence as presented. I am seeing distinct termination boundaries in your new image that seem to more suggest a fossil, possibly brachiopod or bivalve. Is there more to reveal under prep? 2 ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
ynot Posted September 21, 2018 Share Posted September 21, 2018 Sorry, but I do not see a fossil here. I am seeing a tumbled rock with a thin mineralized vein, exposed on one side, that shows some slickensides structures. There also appears to be discreet iron banding that has oxidized. The rock is not chert, way to granular for that. The vein looks like a quartz mineral. 2 Link to comment Share on other sites More sharing options...
Innocentx Posted September 21, 2018 Share Posted September 21, 2018 I'm thinking bivalve for the fragment. Is it concave? "Journey through a universe ablaze with changes" Phil Ochs Link to comment Share on other sites More sharing options...
ynot Posted September 21, 2018 Share Posted September 21, 2018 1 hour ago, Gen. et sp. indet. said: visible on the side of the specimen, not on the photographed surface Please post pictures that show the other sides of the rock. Thank You. Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted September 22, 2018 Author Share Posted September 22, 2018 4 hours ago, ynot said: Please post pictures that show the other sides of the rock. Thank You. Underside (dentrites). Side (laminae). Brachiopod. Link to comment Share on other sites More sharing options...
ynot Posted September 22, 2018 Share Posted September 22, 2018 Thanks for the additional pictures. I agree with the dendrite and brachiopod (or clam) in these pictures. I would like to see a side view of the part that was originally shown. Link to comment Share on other sites More sharing options...
Gen. et sp. indet. Posted September 22, 2018 Author Share Posted September 22, 2018 The surface is kinda twisted... The shell is thin, although distinct when studied in person... Link to comment Share on other sites More sharing options...
westcoast Posted September 22, 2018 Share Posted September 22, 2018 Is it possible that the curved laminations are a fractured surface revealing the internal sedimentary laminations which are clearly visible on the side? Link to comment Share on other sites More sharing options...
ynot Posted September 22, 2018 Share Posted September 22, 2018 I stick with My original statement, a mineralized vien. Link to comment Share on other sites More sharing options...
Innocentx Posted September 22, 2018 Share Posted September 22, 2018 I think it's preserved periostracum similar to this. When I find myalina bivales, many times it's the periostracum that's preserved. "Journey through a universe ablaze with changes" Phil Ochs Link to comment Share on other sites More sharing options...
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