Dear Harry,
The author of Exogyra costata is Say, 1820.
There is quite a lot of information to be found on the internet (try
Altavista searchmachine by typing in Exogyra costata) a.o.
www.physics.uiowa.edu/~cnewsom/fossils/Oysters/exogyra/index.html
Best regards, Henk K. Mienis.
----- Original Message -----
From: Harry G. Lee <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, October 06, 2000 1:05 PM
Subject: Exogyra


> Dear lister, att'n Andy R. and David C.,
>
> I had the good fortune of receiving a gift from a fisherman buddy of mine
> the night before last - a single valve of a pelycypod measuring 115 mm. (4
> 1/2 in.) found at a roadcut E. of U. S. 231 just above the Florida line in
> S. E. Alabama.  It has a coiled groth pattern, 2.3 "whorls" by my
> technique, and is clockwise in direction when viewed from the exterior.
>
> I have seen this illustrated , but the only likeness I found was in
> Ebenezer Emmons' NC report.  It is apparently Exogyra costata - no author
> or date (although I suspect Conrad or Emmons is reponsible).
>
> There are clear similarities to the modern Chamidae in the hinge and
> general morphology, BUT there is only one large adductor scar, suggesting
> that it is more likely an oyster.  I cannot find anything on Exogyra in
> Moore, R. C. or in Thiele.  What gives?
>
> Since it is likely an epifauna bivalve, which valve do I have - the
> attached or "free" one?  The only place on this shell that shows any sign
> of possible attachment is its earliest whorl, which constitutes no more
> than one percent of its surface area.
>
> I find it odd that I, admittedly a non-paleontologist, can find next to
> nothing on this prodigious pelecypod using all the books I have carefully
> assembled for such a search.
> Harry G. Lee
> Suite 500
> 1801 Barrs St.
> Jacksonville, FL 32204
> USA   904-384-6419
> <[log in to unmask]>
> Visit the Jacksonville Shell Club Home Page at:
> http://home.sprynet.com/~wfrank/jacksonv.htm
>
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