Middle Ordovician
Monroe, Orange County, NY.
Mount Merino shale formation
Normansville shale group
Giddings Brook thrust slice

The site is a small, but active, shale quarry. The main part of the outcrop is unfossiliferous
but I did find a few concretions which had weathered out of an old shale outcrop at the
top of the quarry. I found them in the dirt between the shale faces in the picture.
See photo below.

Click on pictures to Magnify

Locality picture 1


Locality picture 2


Unknown brachiopod:: The exterior is smooth, except for some low "bumps"
which may be stumps of spines.


Tentatively ID'd as Oxoplecia gouldi. It doesn't appear to be an exact match
but it's close. The period is right and it's the only Genus with ornamentation
that was similar.

I believe that the larger specimen is the internal cast of the shell along with some internal
structure. I also believe that the smaller specimen is external cast of a shell. These shells
are enclosed in the shale and have to be slowly exposed. An interesting feature is that
a number of the internal casts are overlaid by an external cast (concave) separated by
about a mm. Is it possible that the internal and external casts were formed and then the
shell itself was dissolved...leaving the gap?

Tom Buckley

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