Stocksdale Posted June 28, 2013 Share Posted June 28, 2013 I thought this were Isotelus pygidiums, but I'm not sure. They don't look quite right. This is from the St. Leon roadcut in southeast Indiana. I believe that is Richmondian Stage of the Cincinnatian formation (Ordovician). Somewhere, something incredible is waiting to be known.–Carl Sagan Link to comment Share on other sites More sharing options...
FossilDAWG Posted June 28, 2013 Share Posted June 28, 2013 This is a gastropod (snail) fossil. Each "pygidium" is where a whorl sticks out of the rock. Don 1 Link to comment Share on other sites More sharing options...
Stocksdale Posted June 28, 2013 Author Share Posted June 28, 2013 Aha. The light turns on. I see it now. Somewhere, something incredible is waiting to be known.–Carl Sagan Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted June 28, 2013 Share Posted June 28, 2013 Loxoplocus 1 Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Stocksdale Posted June 28, 2013 Author Share Posted June 28, 2013 (edited) Yep. Feeling a bit silly but glad to know what I have. Here's some that look almost like it from a photo that was posted on the dry dredgers website. Edited June 28, 2013 by Neophytus Elginian Somewhere, something incredible is waiting to be known.–Carl Sagan Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted June 28, 2013 Share Posted June 28, 2013 no worries...we are all on a learning curve w no end. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Lmshoemaker Posted July 29, 2013 Share Posted July 29, 2013 I am curious, why are some of these molds while a few have their shell intact? Link to comment Share on other sites More sharing options...
ghost1066 Posted July 29, 2013 Share Posted July 29, 2013 I am curious, why are some of these molds while a few have their shell intact? Just a thought but maybe as simple as the shell not having weathered away yet. The internal mold was there but for some reason the bits of shell are preserved before weathering out? Link to comment Share on other sites More sharing options...
Herb Posted July 29, 2013 Share Posted July 29, 2013 You have some chain bryozoan (Stomatopora?) on the top shell in your hand. "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
erose Posted July 29, 2013 Share Posted July 29, 2013 (edited) I am curious, why are some of these molds while a few have their shell intact? This is a curious thing that happens in certain stratas. I don't know the exact chemistry involved but I believe it has to do with the different forms of calcite that molluscs use to make their shells. In those Ordovician rocks most clams and snails are just internal molds (=steinkerns) while a few bivalves like Caritodens and some of the gastropods like Cyclonema preserve shell. We have a very similar thing in the Cretaceous of Texas where the vast majority of clams and gastropods are only steinkerns with the exception of scallops, oysters & a few other atypical bivalves. And there are a few exceptions with snails as well. Edited July 29, 2013 by erose 1 Link to comment Share on other sites More sharing options...
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