Dear Harry and other Exogyrophiles,

I don't doubt your fisherman friend, because fishermen always tell the truth
when asked for the location of their honeyholes. <grin> And Exogyra is so
distinctive that I am sure that you identified it correctly. Still, it is
very unlikely that Exogyra would be native to that locality. As David
Campbell and I have both observed, shells are usually not transported for
very great distances without breaking. Although the strata at the
Alabama-Florida line on US 231 are disturbed by karsting (cave and sinkhole
formation), no one has ever reported finding Cretaceous fossils EMBEDDED IN
SEDIMENT anywhere near that locality.

Now, Exogyra can be collected farther north on the same highway, and the
highway is one of the main routes for tourists to the Florida beaches. There
is a lot of traffic by people on vacation. On the whole, it seems more
likely that some child picked up an Exogyra farther north and then a parent
threw it out the car window near the border. As I said, I do believe your
fisherman friend, though I couldn't resist making a joke at his expense.

Andrew K. Rindsberg
Geological Survey of Alabama