Thursday, July 23, 2015

Mesodouvillina varistriata brachiopod from the Kalkberg formation of New York

I recognized today's fossil very quickly due to it's similarity to specimens I have collected from the Givetian stage of the Devonian. This is Mesodouvillina varistriata from the Kalkberg formation of New York. It is a Strophomenid type brachiopod which means that the pedicle valve is convex while the brachial valve is concave. The most identifying feature is the decoration of the shell surface with fine striae which have even finer intermediate striae between them. Otherwise the shell is roughly rectangular in shape with a straight hinge line that is wider than the shell is long.

Pedicle valve
Anterior
Posterior
Profile

The Kalkberg formation is lower Devonian in age (Lockhovian to Pragian stage). I collected this specimen from a roadcut near Shoharie, NY.

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