Nimravis Posted October 15, 2019 Share Posted October 15, 2019 Over the weekend I found this bivalve while collecting at the St. Leon, Indiana roadcut. I posted it in the Hunting Trip section, but received no ID on this piece, so I figured that I would put it here to see if some Member could give me an ID. I have never found one like this before nor can I find a similar one while checking various web pages. Thanks 1 Link to comment Share on other sites More sharing options...
Micah Posted October 15, 2019 Share Posted October 15, 2019 Do you know what formation the particular road cut you found this bivalve is in? This is a good resource for Indiana fossils, but I didn’t see anything matching your shell on this or other resources I looked at... sorry I wasn’t more help. The closest I can find is Ischyrodonta elongata, but it lacks some of the shape and zigzagging of the ridges your specimen has. 1 Link to comment Share on other sites More sharing options...
doushantuo Posted October 15, 2019 Share Posted October 15, 2019 Reticulate ornament would suggest a cryptodont,or praecardiid? Ontaria,Cardiola? 1 Link to comment Share on other sites More sharing options...
Nimravis Posted October 15, 2019 Author Share Posted October 15, 2019 1 hour ago, Micah said: Do you know what formation the particular road cut you found this bivalve is in? The St. Leon Road cut exposes the Whitewater, Liberty, Waynesville and Arnheim Formations. 1 Link to comment Share on other sites More sharing options...
Nimravis Posted October 15, 2019 Author Share Posted October 15, 2019 1 hour ago, doushantuo said: Reticulate ornament would suggest a cryptodont,or praecardiid? Ontaria,Cardiola? Thanks I will have a look. Link to comment Share on other sites More sharing options...
Shamalama Posted October 15, 2019 Share Posted October 15, 2019 Reach out to the Dry Dredgers fossil club in Cincinnati. They have some experts that will be able to ID that rare beauty. Quite the unusual growth line ornamentation for sure! 1 -Dave __________________________________________________ Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrain. - John McPheeIf I'm going to drive safely, I can't do geology. - John McPheeCheck out my Blog for more fossils I've found: http://viewsofthemahantango.blogspot.com/ Link to comment Share on other sites More sharing options...
Nimravis Posted October 15, 2019 Author Share Posted October 15, 2019 1 hour ago, Shamalama said: Reach out to the Dry Dredgers fossil club in Cincinnati. They have some experts that will be able to ID that rare beauty. Quite the unusual growth line ornamentation for sure! I belong to that group, but have never met any of them of had contact with them- I just like to support various clubs- I will do that though Link to comment Share on other sites More sharing options...
erose Posted October 15, 2019 Share Posted October 15, 2019 Caritodens welchi (James) I have a few of these and they are really sweet. 8 Link to comment Share on other sites More sharing options...
Nimravis Posted October 15, 2019 Author Share Posted October 15, 2019 26 minutes ago, erose said: Caritodens welchi (James) I have a few of these and they are really sweet. Thanks much. Link to comment Share on other sites More sharing options...
Nimravis Posted October 16, 2019 Author Share Posted October 16, 2019 k Link to comment Share on other sites More sharing options...
Nimravis Posted October 16, 2019 Author Share Posted October 16, 2019 On 10/14/2019 at 9:55 PM, Micah said: Do you know what formation the particular road cut you found this bivalve is in? This is a good resource for Indiana fossils, but I didn’t see anything matching your shell on this or other resources I looked at... sorry I wasn’t more help. The closest I can find is Ischyrodonta elongata, but it lacks some of the shape and zigzagging of the ridges your specimen has. Thanks Link to comment Share on other sites More sharing options...
Micah Posted October 16, 2019 Share Posted October 16, 2019 13 hours ago, erose said: Caritodens welchi (James) I have a few of these and they are really sweet. What resource did you use to id this? I can’t find mention of this in my resources.... Link to comment Share on other sites More sharing options...
D.N.FossilmanLithuania Posted October 16, 2019 Share Posted October 16, 2019 Looks similar to pteriomorph or ambonychiid, I find similar shells in Silurian. 1 Link to comment Share on other sites More sharing options...
erose Posted October 16, 2019 Share Posted October 16, 2019 9 hours ago, Micah said: What resource did you use to id this? I can’t find mention of this in my resources.... https://pubs.usgs.gov/pp/0695/report.pdf It is listed on the UG stratigraphy site as well: http://strata.uga.edu/cincy/fauna/bivalvia/Caritodens.html 1 Link to comment Share on other sites More sharing options...
doushantuo Posted October 16, 2019 Share Posted October 16, 2019 Actinopteriid? Link to comment Share on other sites More sharing options...
piranha Posted October 16, 2019 Share Posted October 16, 2019 Carlton Brett replied: This is a pterioid bivalve but of course not Caritodens. I do not know the genus; not in the Atlas of Ordovician Life nor Steve Holland’s website, nor the Cincinnatian fossils book. In what part of the Rte 1 outcrop did you find this? Perhaps it is a part of the Whitewater fauna? 1 Link to comment Share on other sites More sharing options...
erose Posted October 16, 2019 Share Posted October 16, 2019 1 hour ago, piranha said: Carlton Brett replied: This is a pterioid bivalve but of course not Caritodens. I do not know the genus; not in the Atlas of Ordovician Life nor Steve Holland’s website, nor the Cincinnatian fossils book. In what part of the Rte 1 outcrop did you find this? Perhaps it is a part of the Whitewater fauna? Pojeta (1971) has an image that isn't quite as ornate but it is the closest I could find online. I will have to look at my catalog and see what my final reference was. I suspect it was in one of the other pubs by Pojeta on bivalves or maybe even the original by James. My Cinci library is fairly extensive so give me a day.... I remember this species well as they are so uniquely ornate and I worked hard to find the proper identification. PS Pojeta has it listed as Pterinea welchi (James). Holland has it listed as Caritodens welchi (James) and listed as being a Liberty species. 2 Link to comment Share on other sites More sharing options...
doushantuo Posted October 16, 2019 Share Posted October 16, 2019 Actually,i am struck by that ornament.* Like you said,it's very distinctive. What i could find that was remotely similar is not strictly Ordovician,an/or perhaps not part of the relevant bioprovince. * perhaps more in an esthetic way than anything else Link to comment Share on other sites More sharing options...
connorp Posted January 28, 2021 Share Posted January 28, 2021 @Nimravis Did you ever get a definitive ID for this bivalve? I just came across this thread while trying to ID a similar specimen I found in the Liberty Formation at St. Leon. Link to comment Share on other sites More sharing options...
Nimravis Posted January 29, 2021 Author Share Posted January 29, 2021 3 hours ago, connorp said: Did you ever get a definitive ID for this bivalve? I just came across this thread while trying to ID a similar specimen I found in the Liberty Formation at St. Leon. Totally forgot about this piece. Just the info that is listed above. I thought I contacted the Dry Dredgers, will check to see if I ever received a response. That is a pretty one that you have. Link to comment Share on other sites More sharing options...
Nimravis Posted January 29, 2021 Author Share Posted January 29, 2021 @connorp FYI, I just checked my old e-mails and see that I did e-mail a member of the Dry Dredgers and he stated the following: The clam is Caritodens. It is the only one in the area that has shell preservation. The ornamentation is typical of larger ones. @erose also stated that it was the same thing during my initial post. 1 Link to comment Share on other sites More sharing options...
erose Posted January 29, 2021 Share Posted January 29, 2021 3 hours ago, Nimravis said: @connorp FYI, I just checked my old e-mails and see that I did e-mail a member of the Dry Dredgers and he stated the following: The clam is Caritodens. It is the only one in the area that has shell preservation. The ornamentation is typical of larger ones. @erose also stated that it was the same thing during my initial post. Caritodens is closer to oysters. Different shell calcite and different preservation. 1 Link to comment Share on other sites More sharing options...
erose Posted January 30, 2021 Share Posted January 30, 2021 Major Edit - had it backwards! So molluscs make their shells from calcite. They can either be a straight up calcite or the variation known as aragonite. Apparently the aragonitic forms show up earlier in time but the two types are already established by the Ordovician if not earlier. Oysters and pectens are the two main types of bivalves that use calcite. Their shells tend to be fossilized where the aragonitic forms tend to dissolve over time. In gastropods the platycerids(sp?) also use more calcite. The result in the fossil record is that we either find fossilized shell or we only find internal molds aka steinkerns. This is true for both the limestone-rich Cincinnatian and the Cretaceous of Central Texas. In the Cincinnatian things like Caritodens, a bivalve, in the pectin group and Cyclonema, a gastropod, in the platycerid group are found with fossilized shell. Where almost all other bivalves and gastropods are only found as internal molds. The same holds true in Texas. Oysters, pectins and muscles as well as some tiny platycerid-type snails preserve shell. Everything else is a steinkern. Having collected both areas the similarities are obvious. 3 Link to comment Share on other sites More sharing options...
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