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  • Jack Kallmeyer posted an update in the group Group logo of Cincinnatian CollectorsCincinnatian Collectors 5 years ago

    5 years ago
    5 years ago

    I usually only keep pelecypod fossils that are well preserved.  Here in the Cincinnatian most have no shell preservation and are only internal molds.  These molds are subject to deterioration and poor preservation such that some no longer look like pelecypods at all.  This attached is an exceptional specimen about 50 mm long.  This is an internal mold with the external shell morphology over printed on it – the ridges on the right.  Note the muscle scar on the left corner.  The black coating is a carbon preservation of the original periostracum layer.  Also note that I am not good at ID for these  so no name…



    • That is an excellent find and extraordinarily preserved! I have a few nicely preserved specimens from near Flemingsburg – where is yours from?

      • This specimen comes from Causeway Road across Brookville Lake. Mollusc preservation is pretty good at the lower end of the exposure – Waynesville Fm.

        • That’s spectacular. I don’t think I’ve ever collected there!

          • I hated this site when I first collected it – found nothing. On my next visit I started finding crinoids so I spent many trips there. I ended up collecting 9 different crinoid species from the Liberty part of this exposure plus one partial ophiuroid. I have suites of crinoids from here with at least two such suites waiting for data collection and publication. Alas, the hot crinoid zone is slumped over now so I have to content myself with looking for well preserved molluscs and trilobites. How sad.

    • Jack, on your Causeway Road bivalve without an ID (very nice specimen BTW), I would suggest it’s Rhytimya sp. There is a similar specimen from the Fairmount pictured in “Review of Ordovician Pelecypods”, Pojeta, Plate 16, figure 10. That one is R. mickelboroughi (Whitfield). But your Waynesville or Liberty specimen is probably R. faberi (Miller), which is found in the Richmondian. Check Dalve 1948 to see if there is a picture of this species.

      • Bill,

        I looked at the Ohio Geological Survey VII and there are quite a few Rhytimya sp. I think you are correct with your ID. Thanks. Dalve 1948 is not illustrated. What publication and year is the Pope reference?