Billymacdaddy Posted March 25, 2019 Share Posted March 25, 2019 Hi everyone, My sons found these in the back yard. I know they are some kind of clam, but not sure about specifics. They have pretty amazing details on them. Thanks in advance for any info. 1 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted March 25, 2019 Share Posted March 25, 2019 Well done to your sons, nice finds! Grammysoidea or the like, i think, definitely bivalves. 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Billymacdaddy Posted March 25, 2019 Author Share Posted March 25, 2019 Thanks! My sons appreciate your congrats, they got little smiles when I told them what u told me. They are quite the fossil hounds! I appreciate everyone here.....what a great website! 1 Link to comment Share on other sites More sharing options...
Zenmaster6 Posted March 26, 2019 Share Posted March 26, 2019 I have seen Grammysoidea found in the Devonian period (especially in New York). Not sure when they went extinct but those clams could be 419 million years old, meaning during the time when fish first appeared and wayyy before dinosaurs. Link to comment Share on other sites More sharing options...
Rockwood Posted March 26, 2019 Share Posted March 26, 2019 Appears to be some overprinting of the external mold features on a steinkern ? Link to comment Share on other sites More sharing options...
Billymacdaddy Posted March 26, 2019 Author Share Posted March 26, 2019 Hi Rockwood, newbie here. In laymen terms what exactly do u mean? Thanks for any info. Link to comment Share on other sites More sharing options...
Billymacdaddy Posted March 26, 2019 Author Share Posted March 26, 2019 16 hours ago, Zenmaster6 said: those clams could be 419 million years old, Very cool! Thanks for the info. Link to comment Share on other sites More sharing options...
DPS Ammonite Posted March 26, 2019 Share Posted March 26, 2019 See this TFF post for 2 possibilities: 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...
Rockwood Posted March 26, 2019 Share Posted March 26, 2019 A steinkern is the sediment that filled the inside of the shell. The contours of the inside of the shell usually do not match those of the exterior. I think the contours on this piece are more like the outside contours were in life, but believe it to be a steinkern. That would mean that during fossilization the stronger folds in the shell were imprinted on the steinkern. If I'm mistaken perhaps @DPS Ammonite will bail me out ? Link to comment Share on other sites More sharing options...
DPS Ammonite Posted March 26, 2019 Share Posted March 26, 2019 5 minutes ago, Rockwood said: A steinkern is the sediment that filled the inside of the shell. The contours of the inside of the shell usually do not match those of the exterior. I think the contours on this piece are more like the outside contours were in life, but believe it to be a steinkern. That would mean that during fossilization the stronger folds in the shell were imprinted on the steinkern. If I'm mistaken perhaps @DPS Ammonite will bail me out ? Rockwood is more or less correct. A steinkern is the filling inside of the clam, AKA an internal mold. I think that the fossil has the characteristics of the exterior of the shell and thus is a cast of the clam if the original shell material has been altered or replaced by another mineral. I guess that technically there could be a steinkern inside the fossil, but 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...
Rockwood Posted March 26, 2019 Share Posted March 26, 2019 17 minutes ago, DPS Ammonite said: Rockwood is more or less correct. A steinkern is the filling inside of the clam, AKA an internal mold. I think that the fossil has the characteristics of the exterior of the shell and thus is a cast of the clam if the original shell material has been altered or replaced by another mineral. I guess that technically there could be a steinkern inside the fossil, but we cannot see it. Maybe there is actually a gradient between the two ? Link to comment Share on other sites More sharing options...
Plax Posted March 26, 2019 Share Posted March 26, 2019 from wikipedia: Pseudomorphs are also common in paleontology. Fossils are often formed by pseudomorphic replacement of the remains by mineral matter. Examples include petrified wood and pyritized gastropod shells. 1 Link to comment Share on other sites More sharing options...
Billymacdaddy Posted March 26, 2019 Author Share Posted March 26, 2019 Thanks for the info. I do understand and appreciate ur knowledge. Link to comment Share on other sites More sharing options...
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