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Date: | Wed, 9 Dec 1998 08:53:17 -0500 |
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Hi all
Last week's thread on fossil oysters and shell thickness made me think
about one of my favorite bivalves, Flemingostrea subspatulata, an
oyster found commonly in the Upper Cretaceous Ripley Formation in the
Southeastern United States. Although I have found numerous specimens
throughout Alabama, the thickest are from a roadcut near Lumpkin,
Georgia. One individual, 12 cm long and 7 cm wide that I found at
this site, had a shell thickness of 6 cm.
As Andrew had mentioned, oysters and pectens have calcitic shells and
are sometimes the only megafauna preserved intact. A question that I
have been meaning to ask is does anyone know of recent gastropods with
calcitic shells? In Ordovician deposits around Cincinnati, gastropods
are common as internal molds. An exception are species of the genus
Cyclonema which are found intact and thought to have had a calcitc
shell. Also, if I am not mistaken, species of the genus Ecphora from
Miocene and Pliocene deposits had calcitic shells.
Just some food for thought from a guy that east raisin bran for
breakfast.
Michael Reagin
Cleveland Heights, Ohio
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