Bronzviking Posted June 14, 2018 Share Posted June 14, 2018 Hi, This is an interesting beach find. It's about 1 1/2" x 1 1/2", Found on Honeymoon Beach, Florida USA. It appears to me a baby Clam Bivalve embedded in a Snail Gastropod Limestone Cast. The clam is about a half of inch at it's widest point and is crystallized. I'm not sure if it is a fossilized shell I'm looking at or a cast of the shell? I've found many snail casts, but not one with another shell in it. Anybody ever see one like this? Thanks for looking! 1 Link to comment Share on other sites More sharing options...
DPS Ammonite Posted June 14, 2018 Share Posted June 14, 2018 You have internal molds of a coiled gastropod and a bivalve since the original shells have dissolved away. Molds are the hardened sediment that was pressed/formed against both the inside and outside of the original fossil or shell. Internal molds are also called steinkerns. A cast is a mineral replacement of a fossil using an exterior and/or and internal mold. 4 My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Miocene_Mason Posted June 14, 2018 Share Posted June 14, 2018 AKA a steinkern. “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
KimTexan Posted June 14, 2018 Share Posted June 14, 2018 Yes, I have seen similar instances where another fossil is preserved inside of a cast or steinkern. I have a number of examples of such. One pair I have both of them even have remnants of the interior of the shell on them. It is a baculite inside a baculite. I’ll have to see if I can find a pic of it and post it. 1 Link to comment Share on other sites More sharing options...
Rockwood Posted June 14, 2018 Share Posted June 14, 2018 52 minutes ago, DPS Ammonite said: You have internal molds of a coiled gastropod and a bivalve since the original shells have dissolved away. The external mold of the bivalve also counts. Bivalve mold, complete. 1 Link to comment Share on other sites More sharing options...
minnbuckeye Posted June 14, 2018 Share Posted June 14, 2018 Very unique!!! Link to comment Share on other sites More sharing options...
DPS Ammonite Posted June 14, 2018 Share Posted June 14, 2018 Rockwood, you are correct. The exterior mold of the bivalve is present even though most of it is in the rock where we cannot see it. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Bronzviking Posted June 16, 2018 Author Share Posted June 16, 2018 Can anyone name this bivalve? Type of clam? Is there anyway to date this fossil? Kim: If you could find similar pictures that would be great! Thx Thanks to everyone who replied! Link to comment Share on other sites More sharing options...
Rockwood Posted June 17, 2018 Share Posted June 17, 2018 1 hour ago, Bronzviking said: Can anyone name this bivalve? Type of clam? Is there anyway to date this fossil? It could be done through context, but the information is not really available in the photo. Link to comment Share on other sites More sharing options...
BobWill Posted June 17, 2018 Share Posted June 17, 2018 For bivalves (and gastropods) you usually need some idea of the external ornamentation for an ID and an internal mold doesn't show that like it might on a cephalopod for instance. 2 Link to comment Share on other sites More sharing options...
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